57th  Congress,  /  HOUSE  OF  RE  PRESENT  ATI  VES.  I  Document 
2d  Session.      )  )    No.  202. 


(  L,  Quality  of  Water,  4 


Water-Supply  and  Irrigation  Paper  No.  76  Series  <  M,  Methods  of  Hydrographic 

(  Investigation,  3 


DEPARTMENT  OF  THE  [INTERIOR 

UNITED  STATES  GEOLOGICAL  SURVEY 

CHARLES  1).  WALCOTT,  DlBECTOR 


OBSERVATIONS  ON  THE  FLOW  OF  RIVERS 

IN  THE 


WASHINGTON 

GOVERNMENT    PRINTING  OFFICE 

1  9  0  3 


f^>\/ 1     a  -\  i  it 


CONTENTS. 


Pago. 

Letter  of  transmittal     7 

Introduction      9 

Methods  of  measuring  velocity  in  river  channels.                       .    14 

Floats                                 .   15 

General  methods  _ . :   15 

Surface  floats  .   15 

Subsurface  or  double  floats^  16 

Rod  or  tube  floats   17 

Weirs   18 

Current  meters  *   19 

Vertical  velocity  curves  on  streams  without  ice  cover  20 

River  stations  at  which  curves  were  obtained   72 

Catskill  Creek  at  South  Cairo,  N.  Y  ..  27 

Esopus  Creek  at  Kingston,  N.  Y   38 

WallMll  River  at  New  Paltz,  N.  Y   28 

Rondout  Creek  at  Rosendale,  N.  Y   28 

Fishkill  Creek  at  Glenham.  N.  Y   28 

Tenmile  River  below  Dover  Plains,  N.  Y     29 

Housatonic  River  at  Gaylordsville,  Conn    29 

Discussion  of  tables     29 

Flow  of  rivers  under  ice,  smooth  and  unbroken  cover   48 

Flow  of  rivers  under  ice,  broken  and  tilted  cover   64 

Quality  of  river  water     67 

Turbidity  and  color   67 

Turbidity   68 

Proposed  turbidity  standard    69 

Method  of  application  of  platinum-wire  process   69 

Method  of  making  observations  »   71 

Color  ■      73 

Color  standards   74 

Filling  the  tubes   75 

Holding  the  tubes   75 

Background  _  ,   75 

Turbid  water   75 

Highly  colored  waters      75 

Cleaning  the  tubes    76 

Alkalinity      76 

Permanent  hardness    76 

Gage  heights  and  discharge  measurements     86 

Index   —       105 

3 


Avery  Architectural  and  Fine  Arts  Library 
Gift  of  Seymour  B.  Durst  Old  York  Library 


1  L  L  DST  RAT  IONS. 


Pages 

Plate  I.  A,  Current  meter  in  use  suspended  from  a  bridge;  B,  Cable  and 

ear  used  to  measure  discharge  of  river   18 

II.  Price  electric  current  meters   20 

III.  Gaging  station  on  Catskill  Creek  at  South  Cairo,  N.  Y   26 

IV.  Gaging  station  on  Esopus  Creek  at  Kingston,  N.  Y   20 

V.  Gaging  station  on  Wallkill  River  at  New  Paltz.  N.  Y   36 

VI.  Gaging  station  on  Rondout  Creek  at  Rosendale,  N.  Y   28 

VII.  Gaging  station  on  Housatonic  River  at  Gaylordsville,  Conn  .  28 
VIII.  A,  Cross  section,  Wallkill  River  at  New  Paltz.  showing  curves  of 
equal  velocity,  as  determined  by  current-meter  measurements; 
B,  Horizontal  velocity  curves  on  Wallkill  River  at  New  Paltz, 
constructed  from  data  obtained  on  the  same  date  as  that  plotted 

in  4  -   30 

IX.  Diagram  showing  results  of  turbidity  observations. .  70 
X.  Tubes  and  disks  for  measuring  in  the  field  the  color  of  river  water  72 
XI.  Diagram  showing  results  of  color  observations  _  _  _  74 

XII.  Diagram  showing  results  of  alkalinity  observations   70 

XIII.  Diagram  showing  results  of  hardness  observations  ..  78 
Fi<;.  1.  Cross-section  curve  on  Esopus  Creek  at  Kingston,  showing  curves 
of  equal  velocity  as  determined  by  current-meter  measurements, 
there  being  no  ice  cover   22 

2.  Mean  vertical  velocity  curves  for  Esopus,  Rondout,  Catskill.  and 

Fishkill  creeks,  and  Wallkill.  Tenmile,  and  Housatonic  rivers  24 

3.  Comparison  of  the  general  mean  velocity  curve  with  the  mean  curve 

for  smooth  bed  and  the  mean  curve  for  rough  bed_  25 

4.  Cross  section  of  Wallkill  River  at  New  Paltz  showing  ice  cover  and 

curves  of  equal  velocity  in  river  channel   48 

5.  "Jean  vertical  velocity  curves  on  Wallkill  River,  with  ice  cover. 

showing  the  effect  upon  thecurveof  variation  in  depth  of  water  60 

6.  Mean  vertical  velocity  curves  on  Esopus  and  Rondout  creeks  and 

Wallkill  River,  under  ice  cover,  showing  the  comparatively  slight 
variation  in  vertical  velocity  curves  of  rivers  of  this  character  01 

7.  Comparison  of  curves  for  various  depths  of  water  under  ice  cover 

with  the  mean  of  all  curves  taken  under  ice  '.   62 

8.  New  folding  turbidity  stick   86 

5 


LETTER  OF  TRANSMITTAL. 


Department  of  the  Interior, 
United  States  Geological  Survey, 

Division  of  Hydrography, 
Washington,  D.  C,  June  28,  1902. 
Sir:  I  transmit  herewith  manuscript  for  Water-Supply  and  Irriga- 
tion Paper  No.  76,  by  H.  A.  Pressey,  entit  led  Observations  on  the  Flow 
of  Rivers  in  the  Vicinity  of  New  York  City. 

Respectfully,  F.  H.  Newell, 

Hydrographt  r. 

Hon.  Charles  D.  Walcott, 

Director  United  States  Geological  Survey. 

7 


Digitized  by  the  Internet  Archive 
in  2013 


http://archive.org/details/observationsonflOOpres 


OBSERVATIONS  ON  THE  FLOW  OF  RIVERS  IN  THE  VICINITY 
OF  NEW  YORK  CITY. 


By  II.  A.  Pressey. 


INTRODUCTK  )X. 

One  of  the  chief  resources  of  the  United  States  is  its  water  supply. 
The  prominent  industrial  position  of  several  States  is  due  largely  to 
the  abundance  of  their  available  water.  It  has  recently  been  stated 
that  "the  preeminent  position  of  the  State  of  New  York  is  due  almost 
entirely  to  her  great  natural  resources;"  that  "her  inland  rivers,  with 
their  great  water  powers,  have  been  in  the  past  and  will  continue  to 
be  in  the  future  a  perpetual  souree  of  wealth,"  and  that  "the  history 
of  the  State's  progress  during  the  nineteenth  century  is  largely  a 
history  of  the  development  of  her  water  resources."  These  remarks 
apply  quite  as  aptly  to  some  of  the  New  England  Stales,  as  they 
could  not  have  held  the  front  rank  in  the  industrial  world  for  so  many 
years  were  it  not  for  the  A  ery  extensive  utilization  of  tile  magnificent 
waterfalls  of  that  region.  In  the  Southern  Atlantic  States  the  great 
developments  during  the  last  few  years  are  due  largely  to  the  develop- 
ment and  utilization  of  water  powers. 

There  is  not  a  State  along  the  Atlantic  coast,  except  Delaware,  that 
does  not  contain  water  powers,  developed  and  undeveloped,  and,  con- 
trary to  the  opinion  of  many,  there  never  was  a  decade  in  the  history 
of  our  country  when  the  development  of  water  power  made  such 
strides  as  during  the  last  ten  years.  According  to  the  ret  urns  of  the 
Twelfth  United  States  Census  the  increase  in  the  utilization  of  water 
power  in  the  United  States  in  the  ten  years  from  1890  to  L900  was 
about  30  percent,  or  472,361  horsepower.  In  some  States  this  increase 
was  remarkable,  as,  for  instance,  in  Maine,  where  in  the  last  decade 
the  developed  power  increased  60  per  cent. 

The  importance  of  our  water  powers  as  a  source  of  wealth  can  hardly 
be  overestimated.  This  x^ower  is  not  confined,  however,  to  the  Kast- 
ern  States,  for  in  the  greal  Central  Northwest,  on  the  Pacific  slope, 
and  elsewhere  there  are  water  powers  of  great  size  and  value,  many 
of  which  form  the  basis  of  the  industrial  life  ol  Large  communities. 
In  the  broad,  flat  plains  of  the  United  States  west  of  the  Mississippi 

0 


10  FLOW  OF  RIVERS  NEAR  NEW   YORK  CITY.  [no. 76. 


the  rivers  are  Valuable  from  another  standpoint.  In  this  region  the 
streams  commonly  hick,  the  fall  required  for  power  development,  but 
here  the  water  supply  is,  perhaps,  more  vital  to  the  life  of  the  region 
Ilia n  in  the  coastal  States.  Great  areas  of  land  depend  for  water 
largely  upon  the  rivers  in  their  vicinity  and  upon  artificial  means  for 
raising  and  distributing  it  over  their  soils.  Without  water  there  can 
be  no  life  in  this  region;  with  water,  vast  areas  can  be  reclaimed  as 
agricult  ural  land  of  great  fertility. 

In  most  parts  of  the  country  the  public  water  supply  of  the  cities 
and  towns  must  be  derived  from  the  rivers.  Large  sums  are  expended 
every  year  in  conducting  water  from  the  streams  to  the  centers  of 
population.  Before  this  money  is  expended  it  is  of  the  greatest 
importance  to  know  that  there  is  sufficient  water  at  all  times  for  the 
use  of  the  town.  Too  often  have  great  hydraulic  works  been  built 
before  proper  investigation  has  been  made  of  the  flow  of  a  stream, 
and  great  financial  loss  has  resulted. 

It  is  to  furnish-  information  upon  which  to  base  estimates  of  avail- 
able wafer  supply  that  the  Hydrographic  Division  of  the  ITnited 
States  Geological  Survey  has  been,  during  the  last  fourteen  years,  col- 
lecting data  in  regard  to  the  flow  of  rivers  in  the  United  States,  and 
their  Variation  from  season  to  season  and  throughout  a  series  of  years. 
The  necessity  for  such  data  is  frequently  brought  to  the  attention  of  the 
engineer,  sometimes  in  a  most  startling  manner.  The  lack  of  this 
information  frequently  leads  to  the  most  disastrous  mistakes  in  fche 
construction  of  hydraulic  works.  One  of  the  best  examples  of  this 
in  the  design  of  a  hydraulic  plant  was  the  construction  of  a  dam  and 
water-power  plant-  at  Austin,  Tex.  After  an  expenditure  of  $1, (500,000 
it  was  found  that  a  grave  mistake  had  been  made  in  the  estimate  of 
t  he  low-water  How.  The  works  were  const  ructed  by  the  city  in  accord- 
ance with  a  vote  of  the  citizens  of  Austin  in  1890.  It  was  estimated 
that  14,000  horsepower  could  be  developed,  and  the  people  felt  that 
their  city  was  to  become  a  great  manufacturing  center.  No  hydro- 
graphic  data  had  been  collected,  except  from  the  hazy  memory  of  the 
"oldest  inhabitant."  In  the  spring  of  1890  a,  measurement  of  flow 
giving  1,000  cubic  feet  per  second  was  taken  as  the  minimum.  This 
estimate  was  more  than  five  limes  too  great,  as  was  shown  by  subse- 
quent measurements.  An  error  of  500  per  cent  had  been  made  m 
the  estimate,  but  t  his  was  not  ascertained  unt  il  t  he  works  were  nearly 
completed. 

Mistakes  of  this  kind  have  occurred  in  every  part  of  the  country 
in  hydraulic  works.  The  Sweetwater  dam  in  California  in  a  good 
example  of  a  project  carried  through  on  insufficient  data.  The 
dam  was  built  after  a  series  of  wet  years  and  was  soon  alter  tilled 
to  overflowing,  so  that  increased  spillways  were  constructed,  but 
since  thai  time  the  water  in  the  reservoir  has  never  reached  an  eleva- 
1  ion  near  the  crest  of  the  spillways,  and  during  most  of  the  t  ime  there 
lias  been  the  greatest  scarcity  of  water. 


I'RKSfSEY  | 


INTRODUCTION. 


11 


The  Bear  Valley  dam  is  a  more  marked  case,  as  fche  reservoir  formed 
by  the  dam  has  been  practically  dry  for  several  years,  so  thai  wells 
have  been  driven  in  the  hoi  loin  of  it. 

The  Gila  Bend,  Arizona,  project  is  another  example  of  the  expendi- 
ture of  a  large  sum — -s(.»< >< >,< it >( > — noon  insufficienl  data,  and  subsequeni 
abandonment  of  the  scheme.  In  this  project  the  dam  was  carried 
away  before  its  completion,  but  had  it  been  completed  the  scheme 
must  have  proved  a  financial  failure. 

Many  diversion  canal  projects  for  irrigation  have  been  either  par- 
tial or  complete  failures  on  account  of  shortage  of  water:  thai  is, 
developments  have  been  made  far  beyond  the  capacity  of  the  stream. 

A  great  number  of  water-power  plants  have  been  constructed  upon 
insufficient  data,  and  later,  auxiliary  steam  has  been  found  neces- 
sary. Allowance  was  not  made  in  the  original  estimates,  so  that  in  a 
number  of  instances  the  project  has  been  found  unprofitable.  Know  1- 
of  the  flood  flow  is  also  of  great  importance  in  designing  the  dams  and 
waste  w  ays. 

Frequently  the  cause  of  such  errors  is  a  complete  ignorance  of  the 
hydrographic  conditions  in  the  drainage  basin  of  the  stream  and 
often  of  the  region  in  which  the  stream  is  located.  In  a  few  eases  no 
adequate  efforts  have  been  made  to  obtain  information;  perhaps  a 
single  measurement  may  have  been  made  at  a  time  when  a  local  res- 
ident informed  the  investigator  that  the  "river  is  now  as  low  as  it 
ever  gets."  In  order  to  test  the  accuracy  of  such  methods,  the  writer 
has  often  asked  old  inhabitants  on  the  banks  of  the  river  as  to  the 
variation  in  the  river  height,  and  lias  been  Informed  that  ikit  is  now 
at  its  lowesi'stage ; "  or,  that  "it  never  falls  more  than  2  or  inches 
below  its  present  height."  At  a  later  visit  to  the  stream  in  the  same 
season  the  river  surf  ace  has  been  found,  to  be  at  an  elevation  2  or  :> 
feet  below  its  previous  stage.  The  word  of  the  oldest  inhabitant  is 
sometimes  fairly  reliable  as  to  high  water,  but  his  information  as  to 
low-water  stages  should  be  carefully  checked,  and  the  fact  thai  a 
number  of  the  inhabitants  say  that  the  river  uever  goes  lower  is  uol 
sufficient  evidence  upon  which  to  construct  hydraulic  works. 

Rainfall  data  are  often  used  iu  discussing  the  variation  of  (low  of 
a  stream,  and  numerous  theories  and  formulas  are  applied  to  show 
thai  the  Cow  can  never  fall  below  a  certain  amount,  these  theories  to 
be  sadly  shaken  later,  when  measurements  are  made  and  the  fads 
ascertained.  In  a  few  cases  greater  weight  has  been  given  to  these 
theories  than  to  actual  measurements,  even  though  the  measurements 
were  made  by  a  careful  and  reliable  engineer.  The  measurements 
were  lower,  perhaps,  than  theory  would  suggest,  and  therefore  the 
measurements  must  be  wrong. 

In  studying  the  flow  of  a  stream  every  possible  source  of  informa- 
tion should  be  utilized — even  the  ideas  of  the  oldest  inhabitants — but 
to  most  engineers  it.  is  very  reassuring  to  know  that  actual  measure- 


12 


FLOW  OF  BIVEBS  jNEAK  NEW   Y OK K  CITY. 


[NO.  70. 


ments  of  the  discharge  have  been  made  and  are  available  for  use.  If 
measurements  of  the  stream  under  consideration  have  not  been  made, 
then  results  obtained  from  measurements  of  rivers  in  the  immediate 
vicinity  can  be  used  to  advantage,  care  being  taken  that  the  hydro- 
graphic,  topographic,  geologic,  and  forest  conditions  in  the  two  basins 
are  similar. 

As  an  example  of  the  difficulties  under  which  a  prospective  investor 
labors,  there  are  now  before  the  writer  reports  upon  a  certain  stream 
in  New  Fork  State  made  by  five  different  engineers,  all  of  good 
standing,  in  which  estimates  of  the  minimum  flow  of  the  stream 
under  consideration  vary  from  0.20  to  0.40  cubic  foot  per  second  per 
square  mile;  that  is,  the  minimum  flow  given  by  one  engineer  is  just 
twice  that  giv  en  by  another.  As  the  development  of  a  water  power  is 
limited  largely  by  the  low-water  flow,  the  uncertainties  arising  from 
such  divergent  opinions  are  apparent.  Since  these  reports  were 
made  (1000-1901)  the  flow  of  this  stream  has  been  measured,  and  the 
lowest  estimate  made  by  the  engineers  has  been  shown  to  be  at  least 
100  per  cent  too  great.  In  estimates  of  this  kind  facts  are  needed — 
thai  is,  actual  measurements  of  discharge. 

No  further  discussion  is  probably  necessary  to  convince  most 
thinking  people  that  the  measurement  of  the  larger  streams  of  the 
United  States  is  an  important  undertaking,  and  that  capital  will  be 
invested  in  power  developments,  irrigation,  sanitary  and  other 
hydraulic  works  more  freely  when  information  as  to  the  flow  of  the 
streams  is  available. 

In  making  measurements  of  streams  it  is  of  course  desirable  that 
rapid  and  economical  methods  be  used,  if  such  are  of  sufficient  accu- 
racy. Methods  of  stream  measurements  have  been  discussed  in 
Water-Supply  Paper  No.  50,  and  it  is  not  the  purpose  of  this  paper  to 
deal  with  that  question  extensively,  but  rather  to  point  out  certain 
facts  developed,  dining  the  last  few  months,  by  measurements  of 
streams  in  the  southern  part  of  New  York  Stale,  with  the  idea  that 
some  of  the  data  obtained  from  these  measurements  may  be  useful  in 
studying  the  Mow  of  other  streams  and  may  assist  in  the  selection  of 
methods  that  will  expedite  the  work  and  yet  give  results  sufficiently 
accurate  for  all  practical  purposes. 

In  considering  the  future  demands  of  the  city  of  New  York  for 
water  several  addit  ional  sources  of  supply  have  been  suggested :  Hou- 
satonic  River,  Tenmile  River,  Wallkill  River,  Rondoul  Creek,  Esopus 
Creek,  and  Catskill  Creek,  the  Hudson  River  or  some  of  its  upper 
tributaries,  Lake  George,  Lake  Champlain,  and  the  Great  Lakes. 
The  three  last-named  sources  have  been  discussed  in  print  somewhat, 
extensively a  and  will  not  betaken  up  Here.  It  has  been  found  that 
the  supply  from  Lake  George  would  not  be  adequate;  thai  Lake 

a  Report  of  Merchants'  Association  of  Now  York  on  tuo  water  supply  of  the  oity  of  Now  York, 

AllgUSt,  l'.MH). 


PKESSEY  1 


INTRODUCTION. 


13 


Champlain  is  at  too  low  an  elevation  for  economical  use,  and  thai  the 
supply  from  the  Great  Lakes  would  entail  great  and  unnecessary 
expense.  The  water  from  the  Hudson  River  mighl  be  taken  aear  its 
headwaters  and  conducted  to  New  York  City  by  a  Long  aqueduct,  or 
the  intake  might  be  Located  just  above  Pouiihkeepsic,  in  which  case 
t  he  water  would  have  to  be  pumped  from  the  river  and  filtered  before 
delivery  to  the  city.  In  either  ease  it  is  important  to  know  the  dis- 
charge of  the  Hudson  at  various  seasons  of  the  year  to  determine  the 
quantity  available  and  also  the  effect  of  the  diversion  of  water  upon 
the  regimen  of  t  he  river. 

The  United  States  Geological  Survey  has  for  several  years  been 
measuring  the  daily  flow  of  streams  throughout  the  United  States, 
the  results  of  these  measurements  being  used  for  different  purposes, 
including  irrigation,  Water-power,  and  sanitary  constructions. 

Measurements  of  flow  of  Schroon  River  at  Warrensburg  and  ol*  the 
Hudson  at  Fort  Edward  and  Mechanicville  have  been  made,  also  of 
the  Mohawk  and  its  chief  tributaries  at  various  points,  and  the  results 
of  these  have  been  published  in  the  annual  reports. 

The  measurements  of  the  rivers  discussed  in  1  his  paper  were  started 
at  the  suggestion  of  Mr.  George  X.  BirdsatL,  chief  engineer  Bureau  of 
Water  Supply,  New  York  City,  in  order  that  data  might  be  available 
for  investigations  as  to  additional  water  supply  for  Xew  York  City. 
The  following  stations  were  established  by  the  United  States  Geo- 
logical Survey  during  the  summer  of  1901  and  have  been  maintained 
continuously  since  that  time. 

Gaging  .stations  on  rivers  near  Xew  York  <  'it if. 
 V  


Drainage  area — 


Stream. 

Location  of  gaging  station. 

Above 
proposed 
reservoir. 

Above 
gaging 
station. 

Above 
month. 

Sij.  miles. 

.SV/.  miles. 

Sq.  miles. 

Teimiile  River  .  . 

Dover  Plains.  N.  Y  .  . 

200 

195 

195 

Hoiisatonic  River  

Gaylordsville.  Conn 

1.020 

1,020 

1,580 

Catskill  Creek  

South  Cairo.  N.  Y 

140 

260 

394 

Esopns  Creek 

Kingston,  N.  Y__.   

242 

312 

417 

Wallkill  River 

New  Paltz,  N.  Y. 

4<>4 

735 

770 

Rondout  Creek  

Rosendale.  N.  Y   ... 

184 

365 

«369 

FishMll  Creek  

Glenham.  N.  Y 

158 

198 

204 

a  Above  junction  with  Wallkill  River. 


A  reconnaissance  of  each  of  these  si  reams  was  made  and  stations 
were  selected  at  points  where  measurements  could  be  mosl  accurately 
made,  and  as  far  as  practicable  at  points  where  LI  was  thought  knowl- 
edge of  the  flow  would  be  most  desired  in  the  future  study  of  these 


14 


KLOW   OF  RIVERS  NEAR  NEW   YORK  CITY. 


[NO.Tfi. 


watersheds  as  sources  of  increased  supply  for  New  York.  rl  m  results 
of  the  observations  aWtshese  stations  have  been  published  in  the 
Water-Supply  Papers  of  the  Survey.  The  height  of  the  water  at  each 
station  has  been  noted  twice  each  day  by  a  local  observer  and  current- 
meter  measurements  have  been  made  at  frequent  intervals  by  a  hydrog- 
rapher.  From  these  meter  measurements  a  rating  curve  lias  been 
drawn  for  each  station  which  shows  the  relation  between  the  height  of 
the  water  in  the  river  and  the  discharge.  From  this  curve  and  the 
daily  mean  gage  height  the  flow  of  the  river  for  each  day  in  the  year 
since  1  he  establishment  of  the  si  at  ion  can  be  determined.  These  data 
will  be  of  the  greatest  importance  to  the  engineers  selecting  t  he  source 
of  supply,  as  they  furnish  the  first  continuous  record  of  the  flow  of 
these  streams  and  give  a  basis  upon  which  to  compute  the  supply 
available  from  each  stream,  which,  with  the  topographic  maps  of  the 
survey  and  the  detailed  surveys  of  the  reservoir  sites,  will  give  com- 
plete data  for  the  estimate  of  the  quantity  of  water  that  can  be  fur- 
nished by  each  of  these  drainage  basins  and  of  the  relative  cost  per 
million  gallons  of  the  supply  from  each. 

In  addition  to  the  measurement  of  the  discharge,  determinations  of 
turbidity,  color,  alkalinity,  and  hardness  have  been  made  upon  each 
of  these  streams  and  are  now  being  continued,  and  it  is  thought  that 
these  data  will  prove  valuable  in  the  final  selection  of  the  new  source 
of  supply.  Results  are  given  in  the  Water-Supply  Papers  of  the 
United  States  Geological  Survey,  and  are  tabulated  at  the  end  of  this 
paper. 

Tn  making  gagings  at  these  stations  it.  was  thought  desirable  to 
investigate  the  varial  ions  of  flow  in  different  parts  of  t  he  river  channel, 
in  order  to  determine  at  what  points  the  velocity  could  be  measured 
to  ascertain  the  mean  velocity  in  the  channel  without  unnecessary 
expense  or  loss  of  time.  Before  taking  up  the  measurements  and  the 
vertical  velocity  curves  const  ructed,  it  may  not  be  out  of  place  to 
describe  briefly  some  of  the  methods  used  for  the  measurement  of 
streams. 

METHODS    OF   MEASURING  VELOCITT  TO   RIVER  CHAN- 
NELS. 

There  are  in  common  use  a  number  of  methods  of  measuring  the 
flow  of  rivers.  In  general  these  involve  the  determination  of  the  mean 
velocity  of  the  current  and  the  area  of  the  cross  section  of  the  st  ream. 
The  latter  is  easily  computed  from  soundings  made  at  frequenl  inter 
vals  across  the  channel.  These  soundings  must  betaken  at  intervals 
so  short  that  the  bot  tom  of  the  river  may  be  considered  a  straight  line 
between  soundings.  Usually  the  velocity  of  the  current  is  deter- 
mined in  sections  of  the  river  channel,  these  sections  extending 
bet  ween  the  points  of  soundings.  The  summation  of  t  he  area  of  each 
of  these  sections  gives  the  total  area  of  the  cross  section.     When  the 


PRKSSEY.  | 


METHODS  OF   MEASURING  VELOCITY. 


L5 


total  flow  of  the  river  is  known  and  is  divided  by  the  area  of  the 
cross  section  the  result,  is  called  the  mean  velocity  of  the  river.  II  is 
this  mean  velocity  that  we  try  to  determine  in  any  method  of  si  ream 
measurement,  but,  as  a  matter  of  Pact,  Lt  can  do1  be  actually  deter- 
mined until  the  total  How  is  known. 

In  the  determination  of  the  mean  velocity  of  the  currenl  there  are  a 
number  ol*  methods  giving  results  more  or  less  accurate,  all  of  which 
should  be  familiar  to  the  engineer,  so  that  the  method  best  suited  to 
the  conditions  at  hand  may  be  applied. 

FLOATS. 

GENERAL  METHODS. 

Floats  are  frequently  employed  to  determine  the  velocity  of  the 
current.  There  are  three  general  types  in  common  use:  First,  sur- 
face floats;  second,  subsurface  or  double  floats;  third,  tube  or  rod 
floats.  The  general  method  of  procedure  is  t  he  same  whichever  form 
of  float  is  used.  The  site  for  making  a  float  measurement  should  be 
on  a  straight  reach,  having  a  fairly  uniform  cross  section.  The  How  of 
the  water  should  be  regular,  without  sudden  rapids  or  stretches  of  st  ill 
water,  and  should  exhibit  no  tendencies  to  form  eddies  or  cross  cur- 
rents caused  by  irregularities  in  the  channel  or  resulting  from  the 
effect  of  a  sharp  bend  above  the  reach.  The  course  of  the  floats 
should  have  a  length  of  from  100  to  300  feet,  and  the  areas  of  cross 
sect-ion  at  the  upper  and  lower  ends  of  t  his  course  should  be  carefully 
determined  bysoundings.  When  courses  more  than  loo  feet  in  Length 
are  selected,  il  is  desirable  that,  additional  cross  sections,  at  equal 
intervals  from  one  another,  should  be  measured.  As  a  preliminary 
step,  a  base  line  should  be  laid  out  by  tape  on  the  bank  as  nearly  as 
possible  parallel  with  the  stream,  and  points  should  be  marked  oppo- 
site the  cross  sections  to  be  used.  If  the  stream  is  not  loo  wide  the 
soundings  in  the  cross  sections  can  be  taken  most  conveniently  along 
a  tagged  rope  stretched  across  the  channel  at  righl  angles  to  the  base. 
If  the  depth  does  not  exceed  4  feet  this  can  be  done  by  wading,  the 
depth  being  read  on  a  rod  graduated  to  feet  and  tenths.  Should  the 
depth  of  the  channel  or  the  temperature  of  the  water  make  wading 
impossible,  a  boat  maybe  used.  On  large  rivers,  where  a  tagged  rope 
can  not  be  employed,  the  boat  from  which  the  soundings  are  to  be 
made  should  be  located  by  simple  triangulation.  Soundings  should 
be  lead  to  tenths  of  a  foot  and  betaken  preferably  at  equal  distances 
apart.  In  deep  rivers  a  tagged  rope  or  chain  with  lead  weighl  can 
be  substituted  for  the  rod. 

SURFACE  FLOATS. 

In  reconnaissance  work,  in  which  the  equipment  is  as  a  rule  limited 
by  transportation  facilities,  surface  floats  consisting  of  chips  will  be 
found  most  convenient.    The  use  of  rod  floats,  though      Ing  more 


16  FLOW   OF  RIVERS  NEAR  NEW    5TORK    CITY.  [no.76. 

directly  the  mean  velocity,  has  many  disadvantages,  and  ..hould  not 
be  attempted  unless  the  time  and  opportunity  permit  of  obtaining 
floats  of  the  required  lengths.  In  the  simplest  case  but  one  man  is 
needed  to  make  the  observations.  The  surface  floats  should  be 
thrown  into  the  stream  a  considerable  distance  above  the  first  cross 
sect  ion.  The  hydrographer  should  attempt  to  start  the  floats,  succes- 
sively, at  different  distances  from  the  shore  in  order  to  determine  the 
velocity  in  different  parts  of  the  channel.  The  time  of  the  passage 
of  each  float  between  the  upper  and  lower  cross  section  should  be 
noted,  preferably  by  a  slop  watch,  and  also  the  position  of  each  float 
with  respect  to  the  tags  on  the  ropes.  This  will  enable  the  hydrog- 
rapher to  determine  whether  or  not  he  succeeds  in  covering  the 
different  parts  of  the  stream,  and  it  will  serve  as  an  aid  in  the  com- 
putation. The  observations  should  be  continued  until  all  parts  of 
the  stream  have  been  covered. 

On  wide  rivers  range  poles  may  be  established  on  opposite  shores 
to  mark  the  upper  and  lower  cross  sections.  The  location  of  each 
float  as  it  crosses  these  imaginary  lines  can  readily  be  recorded  by 
triangulation.  A  light  traverse  plane  table  will  be  found  especially 
useful  in  obtaining  a  graphic  record. 

The  surface  floats  show  approximately  the  surface  velocity  of  the 
stream  at  the  point  of  measurement,  The  results  obtained  by  this 
method  are  subject  to  errors  due  to  wind  and  surface  currents  and 
eddies.  The  velocity  shown  is  that  of  the  surface  of  the  river,  while 
that  required  for  computation  of  discharge  is  the  mean  velocit}r  of  the 
cross  seel  ion.  Unfortunately,  the  relation  of  the  surface  to  the  mean 
velocity  of  the  vertical  is  not  constant,  yet  for  streams  of  the  same 
general  character  of  bed,  banks,  velocity,  etc.,  the  ratio  is  sufficiently 
constant  to  allow  the  mean  velocity  to  be  computed  with  fair  precision 
from  the  surface  velocity  observations. 

SUBSURFACE  OR  DOUBLE  FLOATS. 

The  double  Moat  consists  of  a  small  surface  float  connected  by  a 
line  cord  to  a  larger  subsurface  float,  which  is  so  arranged  that  it 
shall  always  remain  at  the  point  of  mean  velocity  in  the  current.  The 
surface  float  may  consist  of  a  flat  block  of  wood  or  a  tin  water-tight 
drum,  which  floats  upon  the  surface  of  the  water  with  sufficient  buoy- 
ancy to  prevent  the  larger  subsurface  float  from  sinking.  The 
subsurface  float  may  consist  of  two  sheets  of  galvanized  iron  set  at 
rigid,  angles,  weighted  at  the  bottom,  with  an  air-tight  cylindrical 
device  at  the  top,  in  order  that  it  may  at  all  times  keep  its  vertical 
position.  A  round,  hollow  cylinder  of  tin  also  makes  an  excellent 
subsurface  float.  The  tension  on  the  connecting  cord  should  be  at 
least  2  or  :>  pounds,  and  the  cord  should  be  of  silk  and  as  fine  as  pos- 
sible in  order  that  its  resistance  to  the  current  should  not  have  a 
marked  effect  upon  the  velocity  of  the  floats.    The  length  of  the  cord 


PKESSEY.] 


METHODS  OF  MEASURING  VELOCITY. 


17 


should  be  so  regulated  that  the  lower  float  maybe  at  the  point  of 
moan  velocity,  and  the  resistance  of  the  upper  float  arid  the  cord  should 
be  made  as  small  as  practicable.  A  small  flag  should  be  placed  upon 
the  upper  float  in  order  that  its  position  may  be  easily  determined  at 
all  times.  The  chief  objection  to  double  floats  is  the  uncertainty  as 
to  whether  the  cord  is  vertical  and  the  consequent  uncertainty  as  to 
the  position  of  the  subsurface  float.  Another  object  ion  is  the  modi- 
fying effect  of  the  surface  float  and  the  cord  upon  the  velocity  of  the 
lower  float,  as  in  great  depth  the  exposed  surface  of  the  cord  may 
exceed  that  of  the  float.  A  third  objection  is  the  uncertainty  as  to 
the  vertical  position  of  the  lower  float,  as,  owing  to  changes  in  depth 
of  water  and  local  conditions,  the  point  of  mean  velocity  may  change, 
whereas  the  length  of  the  connecting  cord  must  remain  constant  in 
each  run.  This  may  introduce  a  noticeable  error  if  the  increase  in 
depth  is  large,  as  the  retarding  effect  of  the  slow  velocity  near  the 
bottom  of  the  river  will  not  be  felt  by  the  float,  and  the  result  will 
show  too  high  a  velocity.  The  lower  float  may  tip  slightly,  owing  to 
eddies  or  other  causes,  thereby  changing  the  exposed  surface,  or, 
unknown  to  the  observer,  the  lower  float  may  strike  a  bowlder,  caus- 
ing its  velocity  to  be  checked.  In  many  cases  these  objections  would 
not  be  at  all  serious,  but,  in  general,  when  floats  are  to  be  used  better 
results  can  be  obtained,  when  the  depth  is  not  too  great,  by  the  use 
of  rod  or  tube  floats. 

ROD  OR  TUBE  FLOATS. 

These  consist  of  long,  cylindrical  tin  tubes  or  wooden  poles,  2  or  3 
inches  in  diameter,  weighted  at  the  bottom,  so  that  they  will  float 
vertically  with  only  2  or  3  inches  exposed  above  the  water  surface. 
These  rods  integrate  the  velocities  in  a  vertical  section  and  give 
approximately  the  mean  velocity  of  the  current.  It  is  important  that 
they  should  extend  nearly  to  the  bottom,  as  otherwise  the  velocity,  as 
shown,  will  be  too  great,  yet  the  greatest  care  must  be  taken  that 
they  do  not  at  any  time  scrape  upon  the  rocks  at  the  bottom  or  sides 
so  as  to  retard  their  movement.  Rod  floats  are  free  from  many  of 
the  objections  to  double  floats,  as  there  is  no  uncertainty  as  to  their 
position  nor  as  to  the  point  of  mean  velocity  in  the  channel.  They 
are  not,  however,  suitable  for  very  deep  rivers,  or  for  channels  where 
the  depth  varies  considerably,  or  where  weeds  grow  in  the  bed  of  the 
stream.  Mr.  James  B.  Francis  has  stated  that  the  rod  floats  travel  a 
little  faster  than  the  mean  velocity  of  the  water  even  for  the  depth  of 
immersion.  The  float  will  be  subject  to  pressures  proportional  to  the 
square  of  the  relative  velocities  of  the  water  at  different  points,  and 
when  it  has  attained  its  full  speed  there  will  be  equilibrium  between 
these  different  pressures.  This  equilibrium  may  exist,  however,  when 
the  speed  of  the  float  is  somewhat  different  from  the  mean  velocity  of 
the  water,  the  latter  being  the  arithmetical  mean  of  all  the  different 

irr  70 — 03  2 


18 


FLOW   OP    RIVERS    NEAR    NEW    YORK  CITY. 


|  No.  Tf). 


velocities  throughout  the  depth  of  immersion.  Tin  following  formula 
for  correcting  an  observed  velocity  was  derived  by  James  B.  Francis 
from  his  Lowell  experiments: 


Where  V„,  is  equal  to  true  mean  velocity  in  vertical,  V„  equals 
observed  velocity  of  tube,  d  equals  mean  depth  along  path  of  tube, 
dl  equals  depth  of  immersion  of  tube. 

Col.  Allan  Cunningham"  has,  however,  calculated  that  such  floats 
move  somewhal  slower  than  the  water  in  which  they  are  immersed. 
The  error  of  assuming  that  the  velocity  of  the  tube  represents  the 
mean  velocity  in  the  vertical  will  not  be  material  unless  tubes  too 
short  are  used,  in  which  case  1  he  velocity  as  shown  by  the  tube  should 
be  somewhat  reduced. 


By  the  method  of  weirs  the  discharge  of  the  stream  is  computed  by 
means  of  an  empirical  formula,  which  varies  for  differenl  types  of 
dams  or  weirs.  On  creeks  or  small  rivers  it  is  sometimes  practicable 
to  build  a  timber  weir  across  the  channel,  causing  the  total  flow  of  the 
stream  to  pass  over  the  sharp  edge  of  the  weir  crest.  By  observing 
the  head  on  the  weir,  computations  of  the  flow  can  be  made.  This  is 
probably  the  most  accurate  method  applicable  to  small  streams.  On 
large  rivers,  however,  the  cost  of  a  weir  is  usually  so  great  as  to  be 
prohibitive,  so  that  if  thereis  not  aweirordam  already  in  the  stream 
it  is  necessary  to  resort  to  measurements  by  floats  or  current  meters. 

On  many  of  the  rivers  of  moderate  size  the  conditions  are  unfavor- 
able for  successfully  applying  either  of  these  methods.  For  instance, 
on  streams  used  for  manufacturing  purposes  dams  occur  at  frequent 
intervals,  interrupting  the  regular  flow,  and  in  many  cases  holding 
back  the  night  flow  for  use  during  the  following  day,  so  that  the  dis- 
charge during  the  night  may  be  either  nothing  or  a  very  small  per- 
centage of  the  day  flow.  Then,  too,  the  shutting  down  of  the  mill 
wheels  for  an  hour  at  noon  may  have  a  pronounced  effect  upon  the 
results  of  float  or  meter  measurements  made  below  the  mill.  Unfor- 
t  unately  these  variat  ions  are  notalways  apparent  to  the  hydrographer, 
and  surprise  and  annoyance  are  caused  by  finding  that  the  river 
height  differs  by  several  tenths  from  the  gage  as  read  by  the  regular 
observer  a  shori  time  before  the  hydrographer  arrived  at  the  station. 

Under  the  conditions  described,  better  results  can  undoubtedly  be 
obtained  if  there  exists  upon  the  st  ream  a  good  dam  which  can  be  used 
as  ;i  weir.  It  should  have  a  Level,  even  cresl  and  a  constant  cross 
section,  w  ith  sufficient  pondage  to-reduce  the  velocity  of  approach, 
and  it  should  be  free  from  leakage.     Masonry  dams  are  better  for 

"Recent  hydraulic  experiments:  Min.  Proc.  Inst.  Civil  Eng.,  Vol.  LXXI  L88& 


WEIRS. 


B.    CABLE  AND  CAR  USED  TO  MEASURE  DISCHARGE  OF  RIVER 


pressky.]  METHODS  <>F  MEASURING  VELOCITY. 

tliis  purpose,  for  they  are  more  Likely  to  be  tight  and  to  have  an  even 
crest.  Timber  dams,  although  level  when  lirst  constructed,  are  likely 
i<>  settle  at  various  points,  thus  producing  an  uneven  cresl  elevation. 
There  are,  however,  many  good  timber  dams  practically  free  from 
Leakage  and  with  crests  sufficiently  uniform  for  accurate  work. 

Having  selected  a  dam  as  the  proper  site  Cora  station,  a  careful 
survey  must  he  made  of  the  cresl  Line  and  of  the  upper  and  Lower 
slopes,  so  that  it  can  be  compared  with  oilier  dams  or  with  experi- 
mental sections  for  which  the  coefficients  of  flow  are  known.  The 
experiments  of  .lames  B.  Francis,  of  Fteley  and  Stearns,  and  of  John 
R.  Freeman,  George  W.  Rafter,  and  others  at  Cornell  University, 
have  given  coefficients  upon  many  sections  of  various  forms.  Il  is 
pr  bable  that  the  dam  seleei<>d  for  the  station  will  not  be  exactly  like 
any  of  the  experimental  forms,  but  it  will  resemble  some  of  them  so 
closely  that  coefficients  can  be  selected  for  the  compulations. 

When  the  mill  gates  are  open  a  part  of  the  flow  is  diverted  from  the 
river  through  the  mill  race,  the  gates,  and  the  tailrace. 

The  amounl  of  the  diversion  must  of  course  he  measured  and  added 
to  the  quantity  flowing  over  the  dam,  in  order  to  determine  the  total 
discharge  of  the  stream.  Tn  many  factories  the  quantity  flowing 
through  the  wheels  varies  from  day  to  day,  and  also  during  different 
hours  of  t  he  day,  so  t  hat  careful  records  must  he  kepi  of  gate  openings, 
in  order  thai  proper  allowance  may  he  made  for  these  varial  ions.  The 
size  and  the  make  of  the  water  wheels  must  he  ascertained,  and  the 
wheels  he  used  as  water  meters  for  the  determination  of  the  flow 
through  them.  Many  of  the  modern  wheels  have  been  carefully  rated. 
Where  such  rating  have  not  been  made,  usually  records  of  wheels  of 
the  same  type,  though  possibly  of  different  makes,  can  he  found  and 
the  records  he  compared.  Wafer  wheels  as  meters  give  fairly  accu- 
rate records  of  the  discharge. 

The  Chezy  formula  or  surface-slope  method  has  been  extensively  em- 
ployed in  gaging  large  rivers.  The  proper  coefficients  to  he  applied 
are  usually  determined  from  the  auxiliary  formula  of  Gauguillet 
ami  Kutter.  One  difficulty  in  the  application  of  this  method  lies  in 
the  selection  of  suitable  friction  factor  or  coefficient  of  roughness. 

CURRENT  METERS. 

The  current  meter  has  been  found  best  adapted  to  t  lie  general  meas- 
urements made  hy  the  Tniled  States  Geological  Survey,  and  is  used 
almost  exclusively  in  its  hydrbgraphic  investigations.  (IMs.  I  and  II.) 
( )ccasionally,  however,  either  a  meter  is  not  available  or  the  conditions 
are  not  favorable  for  its  use.  In  such  cases  weirs  or  floats  have  been 
used,  though  a  Pitot's  tube,  hydrometric  pendulum,  or  hydrometric 
balance  might  in  exceptional  case  he  used  to  advantage. 

The  current  meter  has  been  described,  and  inst  met  ions  for  the  care 
and  use  of  the  instrument  have  been  given  in  Water-Supply  Paper 


20 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY. 


[no.  76. 


No.  56.  The  object  of  the  present  discussion  is  to  give  a  few  addi- 
tional facts  as  to  the  *pdint  at  which  the  meter  should  be  held  to 
determine  the  mean  velocity  in  a  channel,  as  deduced  from  meas- 
urements recently  made  upon  rivers  in  the  southern  part  of  New 
York  Slate.  The  current  meter  may  be  used  to  determine  the  veloc- 
ity of  a  river  in  four  ways:  First,  by  making-  point  measurements 
at  a  depth  corresponding  to  the  approximate  position  of  the  thread 
of  mean  velocity;  second,  by  deducing  the  mean  velocity  from  obser- 
vations made  at  other  points  in  the  same  vertical;  third,  by  the 
integration  method;  fourth,  by  point  measurements  made  at  regular 
intervals  throughout  cross  sections  of  t  he  river.  In  the  first  two  of 
these  methods  it  is  important  to  know  the  relation  between  the  veloci- 
ties  at  various  points  in  flic  seel  ion.  In  the  first  method  the  position 
of  mean  velocity  must  be  known,  and  in  the  second  method  the 
relation  between  the  surface  velocity,  or  the  velocity  at  mean  depth, 
to  the  mean  velocity  must  be  known.  In  either  of  these  cases  the 
form  of  the  vertical  velocity  curve  will  determine  the  coefficient  to  be 
applied  to  the  observations. 

VERTICAL  VELOCITY  CURVES  ON  STREAMS  WITHOUT  ICE 

COVER. 

Studies  of  the  vertical  velocity  curve  made  on  the  Mississippi  River 
by  Humphreys  and  Abbott,  on  the  Connecticut  by  T.  G.  Ellis,  on 
the  Merrimac  flume  by  Wheeler  and  Lynch,  on  the  Potomac  by  C.  C. 
Babb,  and  recent  experiments  by  others,  notably  those  at  Cornell 
University  by  E.  C.  Murphy,  indicate  that  the  point  of  mean  velocity 
in  a  given  vertical  section  is  at  a  depth  varying  from  six-tenths  to 
two- thirds  of  the  total  depth  of  the  section,  measured  from  the  sur- 
face down.    The  values  found  in  the  experiments  were  as  follows: 

Depth  from  surface  of  point  of  mean  velocity. 


Experimenter 


Cynis  C.  Bahh 
Humphreys  and  Abbott 

T.  G.  Ellis  

E.  C.  Murphy  

Wheeler  and  Lynch   


Stream. 


Potomac  River  . . . 
Mississippi  River. 
Connecticut  River 
Cornell  flume  - . . 
Merrimac  flume  - 


Depths. 


0.  58 

.64 
".  65 
.<>7 


"For  depths  between  6  and  '.» fV<'t.  tlx-  proportionate  depth  of  point  of  moan  velocity  becoming 
less  as  the  depth  of  the  water  decreased,  and  becoming  0.55  for  depths  of  water  between  1  and  2 
feet. 


The  Cornell  experiments  indicate  that  measurements  made  al  six- 
tenths  of  the  depth  yield  results  3.5  per  cent  too  large,  the  depth  of 


PRICE  ELECTRIC  CURRENT  METERS. 


PHKSSF.Y  | 


VERTICAL   VELOCITY  (TKVES. 


21 


mean  velocity  being  nearly  two-thirds  of  the  depth.  The  measure- 
ments at  Cornell  were,  however,  made  in  the  canal,  the  cross  sections 
of  which  have  a  greater  ratio  of  depth  to  width  than  most  riveis,  and 
decidedly  more  than  the  Mississippi,  Connecticut,  and  Potomac,  upon 
which  the  above  coefficients  were  obtained.  There  can  be  no  doubt 
but  that  the  difference  in  the  ratio  of  the  depth  to  w  idth  is  a  factor 
likely  to  affect  the  position  of  mean  velocity. 

The  bottom  and  sides  of  the  channel  retard  the  flow  close  to  them 
in  proportion  to  their  roughness,  this  retardation  being  due  more  to 
the  impeding  of  the  flow  by  eddies  than  by  friction  alone  The  retarda- 
tion of  the  surface  velocity  has  been  attributed  to  the  rising,  by  vert  ical 
motion,  of  the  lower  water  to  the  surface  after  being  checked  in  itsflow 
by  striking  against  the  rough  bottom  and  sides  of  the  channel.  The 
variation  of  the  velocity  in  the  river  channel  is  shown  in  PI.  VIII 
(p.  30)  and  fig.  1. 

Mr.  Frederick  P.  Stearns  has  attributed  the  reduction  of  surface 
velocity  to  the  general  retarding  of  the  layers  of  water  adjacent  to 
the  banks  of  the  stream,  this  water  rising  to  the  surface  and  thereby 
making  the  edges  of  the  channel  higher  than  the  center  ami  causing 
a  flow  of  the  slowly  moving  water  from  the  sides  toward  the  mid- 
dle, thereby  decreasing  the  surface  velocity,  depressing  the  point 
of  maximum  velocity,  and  lowering  in  general  the  filament  of  mean 
velocity.  This  depression  of  the  maximum  velocity  is  known  to 
become  more  pronounced  with  an  increase  in  the  roughness  of  the 
lining,  in  the  steepness  of  the  banks,  and  in  the  ratio  of  depth  to 
width.  In  an  extreme  case  of  a  wide,  shallow  stream,  where  the  bot- 
tom merges  imperceptibly  into  the  banks,  maximum  velocity  occurs, 
under  normal  conditions,  at  or  very  near  the  surface  of  the  center 
of  the  stream.  On  the  other  hand,  in  a  deep,  narrow  channel,  as 
for  instance,  in  a  canal  with  vertical  sides,  the  maximum  velocity 
occurs  a  considerable  distance  below  the  surface,  and,  as  the  Cornell 
experiments  indicate,  this  depression  may  amount  to  as  much  as  one- 
third  and  even  two-fifths  of  the  total  depth.  Evidently,  then,  in  sneh 
cases  depression  of  maximum  velocity  must  result  in  a  Lowering  of 
the  thread  of  mean  velocity,  and  engineers,  in  making  unit  meas- 
urements for  mean  velocity,  should  bear  in  mind  thai  while  the  ODSer- 
vations  at  six-tenths  depth  give  fair  values  for  mean  velocity  in  wide, 
shallow  rivers  this  ratio  should  be  increased  to  two-thirds  in  the  case 
of  canals  and  flumes  or  narrow  natural  channels. 

The  friction  of  flowing  water  against  the  air  has  a  similar  influence, 
and,  though  in  general  less  marked,  it  may,  in  the  ease  of  a  Strong 
upstream  wind,  have  a  decided  influence  upon  the  surface  velocity 
and  the  point  in  the  vertical  of  the  maximum  and  mean  velocity.  <  >n 
account  of  these  resistances  on  tin-  bed  ami  bank  of  a  stream,  ihr 
maximum  velocity  of  the  river  in  a  straight  reach  is  found  in  therm- 


22  FLOW   OF  RIVERS  NEAR  NEW  YORK  CITY.  wo.7« 


tral  portion  'of  the  stream,  and  somewhat  below  the  surface — the 
actual  position  depending  upon  the  size  and  condition  of  the  river 
and  the  velocity  of  How.  The  velocity  increases  from  the  surface 
downward  for  a  short  distance — say,  one-tenth  of  the  depth — and  then 
decreases  down  to  the  bottom,  where  it  readies  the  minimum. 

Various  writers  who  have  studied  the  form  and  equation  of  the 
curve  representing  the  variation  in  velocities  in  a  vertical  section  have 


Fie.  L— Cross  section  on  Esopus  Creek,  at  Kingston,  showing  carves  of  equal  velocity  as 
determined  by  current-meter  measurements,  there  being  no  ice  cover. 


come  to  different  conclusions  as  to  the  form  of  this  curve,  flic  inclined 
straight  line,  flic  parabola  with  horizontal  axis,  the  parabola  with  ver- 
tical axis  and  vertex  ator  below  the  surface,  1  he  ellipse,  and  1  lie  hyper- 
bola each  having  its  advocates.  Humphreys  and  Abbotl  showed  by 
their  experiments  on  the  Mississippi  River  thai  the  curve  did  nol  dif- 
fer  materially  from  a  parabola  having  its  axis  parallel  to  the  surface 
and  a  I  the  depth  below  1  he  surface  of  the  position  of  maximum  veloc- 


PRESSRY.l 


VERTICAL  VELOCITY  CURVES. 


23 


ity,  the  abscissas  representing  the  velocities  at  the  differenl  depths 
and  the  ordinates  the  vertical  distances  of  these  depths  from  the 
point  of  mean  maximum  velocity.  In  the  Mississippi  River  experi- 
ments the  position  of  maximum  velocity  was  on  an  average  nearly 
one-third  of  the  whole  depth  below  the  surface,  varying  with  the 
direction  of  the  wind.  Bazin  also  Pound  that  the  vertical  velocity 
curve  was  in  the  form  <>f  a  parabola,  the  curve  varying  with  different 
channels  and  the  position  of  maximum  velocity.  Professor  von 
Wagner  agreed  with  the  above  experimenters,  but  found  thai  the 
curve  differed  Prom  the  parabola  toward  the  bottom  and  near  the 
surface,  and  that,  the  point  of  maximum  velocity  varied  from  a  Little 
below  the  surface  to  a  little  over  one-fourth  of  the  full  depth. 

The  exact  mathematical  form  of  a  vertical  velocity  curve  is  not  a 
vital  question  in  the  measurement  of  streams,  but  it  is  greatly  to  be 
desired  that  the  relation  between  the  surface,  maximum,  and  mean 
velocities  should  be  known,  so  that  if  any  one  of  these  be  measured 
accurate  computations  of  the  flow  can  be  made,  and  so  that  if  the 
velocity  of  the  stream  be  measured  at  some  particular  point  the 
mean  velocity  of  the  whole  section  can  be  calculated.  Il  has  been 
shown  by  a  series  of  measurements,  the  results  of  which  are  given 
herein,  that  the  typical  vertical  velocity  curve  is  in  general  of  the 
form  shown  in  fig.  2;  that  the  surface  velocity  is  somewhat  greater 
than  the  mean;  that  the  maximum  velocity  is  below  the  surface  but 
above  mid  depth;  and  that  the  point  of  mean  velocity  is  from  0.6  to 
two-thirds  of  the  depth  below  the  surface.  The  relation  between  the 
surface  velocity  and  the  mean  velocity  is,  of  course,  important  in  the 
use  of  surfjfce  floats  and  current  meters  when  the  velocity  is  meas- 
ured only  near  the  surface,  for  some  coefficient  must  always  be 
applied  to  obtain  the  mean  velocity  in  the  vertical  section.  In  this 
connection,  some  results  obtained  by  Mr.  J.  \\.  Lippincotl  on  rivers 
in  southern  California,  in  April,  1902,  are  of  interest: 

On  the  Sacramento  River,  at  Jellys  Ferry,  observations  for  velocities  have  been 
taken  at  the  top.  middle,  and  bottom  of  each  section  at  intervals  of  20  feet.  The 
channel  is  of  bowlders  and  has  a  depth  of  from  3  to  5  feet  in  the  low- water  stages. 
The  relation  of  the  mean  velocity  to  the  top  velocity  on  each  section  was  deter- 
mined, and  then  the  mean  ratio  for  the  entire  measurement.  The  measurements 
were  arranged  in  0  groups  according  to  gage  heights.  In  the  first  group  the  mean 
velocity  was  87  per  cent  of  the  surface  velocity;  in  the  second  88;  in  the  third  88; 
in  the  fourth  Si);  in  the  fifth  ST:  in  the  sixth  87.  The  last  group  represents  the 
highest  water.  The  mean  of  80  measurements  gives  a  ratio  of  88  per  cent.  In 
this  case  the  coefficients  are  (mite  constant. 

A  determination  on  the  Tuolumne  River,  at  Lagrange,  also  gives  a  coefficient  of 
88  per  cent.  This  river  lias  a  pebbly  or  stony  bed.  and  the  depths  range  from  1.12 
to  1.84  feet.    The  velocities  range  from  8  to  5  feet. 

On  the  smaller  rivers  the  determinations  were  less  satisfactory,  because  when 
depths  become  as  low  as  1  foot,  top,  middle,  and  bottom  velocities  were  seldom 
observed  with  meters,  and  unless  we  had  three  observations  tor  velocity  the  mean 


24 


FLOW   OF  RIVERS  NEAK  NEW  YORK  CITY. 


[no.  76. 


velocity  was  not  considered  sufficiently  accurate  to  justify  a  comparison  with 
the  surface  velocity. 

The  relative  irregularities  of  the  beds  of  the  smaller  streams  also  introduced 
wider  ranges  in  the  relation  of  surface  to  mean  velocities. 

On  the  San  Gabriel  River  the  following  results  were  obtained  at  different  points 
on  the  stream:  0.83,  0.94,  0.95,  0.89,  0.90,  0.98;  mean,  0.92. 


50 


I 

Vlthout 

ice 

\ 

\ 

V 

\ 
\ 

j 

1 

Tent 
 /~~/sh, 

n/'/e 
aton/'c 

-pit 
k 

ML 

i 

I 
I 

- — jEsol 
—  /for, 

w// 

dout 

i  i/ 
hi/ 

— 

—Cats, 

W// 

li 

/  IK 

— ?fl 

M 
£  



/a 

/  /A 

4? 

■/A 

*// 

'  <~*  / 

9/ 

70  80  90  100 

Velocity  in  terms  of  mean  velocity  100. 


110 


1:20 


180 


Fig.  2.— Mean  vertical  velocity  curves  for  Esopus,  Rondont,  Catskill,  and  Fishkill  creeks, 
and  Wallkill.  Tenmile.  and  Housatonic  rivers. 


On  the  Santa  Ana  River  the  following  determinations  were  made  at  Warm 
Springs:  0.96,  0.95,  0.91,  0.86,  0.90.  0.91,  0.96,  0.93;  mean.  0.92. 

The  channels  of  these  two  streams  are  relatively  rough,  the  water  snrfac  is 
usually  from  10  fco  20  feet  in  width,  and  the  depths  vary  from  0.25  foot  to  1  foot 
for  the  stage  of  water  observed  upon.  Tt  is  rather  singular  to  note  that  the 
determination  of  these  coefficients  in  the  smaller  and  relatively  rough  channels 
shows  a  higher  value  than  in  the  larger  channels.    As  previously  remarked,  how- 


PRESSEY.] 


VERTICAL   VELOCITY  CURVES. 


25 


ever,  the  determinations  for  the  San  Gabriel  and  the  Santa  Ana  an-  not  considered 
as  entirely  satisfactory  nor  as  reliable  as  the  determination  for  the  Sacramento. 
It  is  possible  that  the  coefficients  which  we  have  determined  for  the  smaller 
streams  are  too  high,  owing  to  the  fact  that  the  current  meter  could  not  be  placed 
in  the  slowest  film  of  water  immediately  adjacent  to  the  bottom  and  sides  of  the 
channel,  so  that  the  mean  velocity  as  shown  may  be  slightly  above  the  true 


\ 

 \ 

\ 

! 

—  Mea 
— Mea/ 
— -Meat 

n  or7t 
?  of *26 
7  of 25  c 

curiae 
zurises, 
:un/es, 

s,gener 
smooth 
~ough  6 

3/  condi 
bed 

h  'ons  '< 

 i 

i 

/ 

f 

/ 

// 

-# 

i 

/ 

/// 

ft 
/// 

9 



V 

 ^ 

50  60  70  80  90  100  110  120  130 

"Velocity  in  terms  of  mean  velocity  100. 
Fig.  3.— Comparison  of  the  general  mean  velocity  curve  with  the  mean  curve  for  smooth  bed 
and  the  mean  curve  for  rough  bed,  I  Note:  The  general  mean  curve  includes  all  data  obtained 
in  78  vertical  velocity  curves;  the  mean  curve  for  rough  bed  includes  the  data  for  25  vertical 
velocity  curves,  and  the  mean  curve  for  smooth  bed  includes  the  data  for  86  vertical  velocity 
curves.    All  of  these  curves  were  taken  when  there  was  no  ire  cover.) 


mean  velocity.  This  error  would  be  relatively  greater  in  small  than  in  large 
streams,  however.  In  the  measurements  of  the  small  stream  a  Price  acoustic 
meter  has  been  used,  which  permits  the  center  of  tin- meter  to  be  placed  within 
3  inches  of  the  bed  of  the  creek. 

In  consideration  of  the  above  data  it  is  believed  that  for  ordinary  streams  dis- 
charging KM)  cubic  feet  per  second  of  water,  or  less,  on  stony  beds,  that  0.9  of  the 


26 


FLOW   OF  RIVERS  NEAR  NEW  YORK  CITY. 


[NO.  7t). 


mean  surface  velocity  for  the  section  will  represent  the  mean  velocity  for  that 
section,  said  surface  velocities  being  observed  at  numerous  points  across  the 
stream. 

"  With  the  object  of  determining  the  rat  io  between  the  maximum  sur- 
face velocities  and  the  mean  velocity,  Do  Prony  made  some  experi- 
ments in  wooden  troughs,  and  Messrs.  Baldwin, Whistler, and  Slosaon 
in  channels  lined  witli  planks.  The  coefficients  obtained  for  convert- 
ing the  observed  surface  velocity  into  mean  velocity  were  0.8116  by  Do 
Prony  and  from  0.810  to  0.847  by  the  latter  observers  in  different 
channels.  Subsequent  experiments  indicate  that  the  coefficient  is  gen- 
erally comprised  within  the  limits  of  0.8  and  0.9,  depending  upon  the 
size  of  the  channel  and  the  nature  of  the  bed.  The  Mississippi  River 
experiments  show  the  coefficients  to  exceed  0.9,  but  it  is  quite  possible 
that  i  he  influence  of  the  long  connecting  cord  and  surface  float  caused 
too  large  values  to  be  recorded  for  the  velocities  toward  the  bottom, 
and  thus  gav  e  too  high  a  value  to  the  mean  velocity,  as  Mr.  Robert 
Gordon,  in  cheeking  his  experiments  on  the  Irraw;#ldi  with  a  current 
meter,  obtained  considerable  reduction  in  the  velocities  approaching 
the  hot  lorn  compared  with  those  obtained  by  double  floats.  The 
coefficient  would  be  greatest  for  large,  deep  rivers  with  smooth,  uni- 
form channels,  and  least  for  small,  shallow  streams  with  rough  beds. 
Messrs.  Darcy  and  Bazin  derived  from  their  experiments  the  follow- 
ing formula  giving  the  relation  between  the  maximum  velocity  and 
the  mean  velocity: 

U-V=2/>.om;n/r  s 

where  U  is  the  maximum  velocity  in  feet  per  second,  the  mean 
velocity,  H  the  hydraulic  radius  in  feet,  and  S  the  slope. 

The  variation  in  the  coefficient  to  be  applied  to  the  surface  velocity 
gives  rise  to  a  possible  error  large  enough  to  preclude  the  use  of  this 
method  of  measurement  when  accurate  results  are  desired.  As  a 
quick  method  it  may  often  be  used,  and  in  a  few  cases,  as,  for  instance, 
at  the  time  of  high  floods,  when  if  is  impossible  to  use  other  means, 
the  results  obtained  by  this  method  may  be  of*  considerable  value. 

The  mean  of  7S  velocity  curves  taken  upon  rivers  in  the  southern 
part  of  New  York  State,  described  further  on  in  this  paper,  shows  that 
tlie  mean  velocity  was  0.87  of  the  surface  velocity  in  the  vertical  sec- 
tion (shown  in  tig.  :>).  This  coefficient  varied  from  0.82  in  the  case  of 
Catskill  ('reek  loo.ii:}  on  Fishkill  Creek  (fig.  2).  It  will  be  noted  that 
these  coefficients  apply  to  the  mean  velocity  in  the  vertical  in  which 
the  float  is  run.  If*  only  one  surface  float  is  used,  and  that  in  the 
center  of  ihe  river,  or  point  of  maximum  velocity,  it  appears  thai  0.8 
is  the  proper  coefficient  to  apply,  though  the  chances  of  error  are 
much  greater  1  ban  when  surface  float s  are  used  at  intervals  across  the 
channel. 


a  From  Rivera  and  <  ianals,  vol.  I,  p  38,  by  L.  P.  Vernon-Harbowrt. 


PRESSKV.J 


VERTICAL  VELOCITY  CURVES. 


27 


RIVER  STATIONS  AT  WHICH  CURVES  WERE  OBTAINED. 

In  June,  1901,  a  reconnaissance  was  made  of  ('at skill,  Ksopns, 
and  Rondoul  creeks,  and  Wallkill  River  west  of  the  Hudson,  and 
Fishkill  Creek  and  'Ten mile  and  Housatonic  rivers  east  of  the  Hudson. 
Nearly  the  entire  length  of  eaeli  Stream  was  traversed,  and  a  site  for 
a  gaging  station  selected  on  each.  Early  in  .Inly  the  stations  were 
established,  with  the  exception  of  that  on  Tonniile  River,  which  was 
established  in  September  of  the  same  year.  Persons  living  near  at 
hand  were  employed  as  gage  readers  to  take  observations  of  the  stage 
of  the  stream  twice  each  day.  Mr.  A.  E.  Place  was  in  charge  of 
these  stations  until  September,  L901,  when  Mr.  W.  W.  Schlecht  was 
placed  in  charge  as  resident  hydrographer.  The  measurements  given 
in  this  paper  were  obtained  by  Messrs.  Place  and  Schlecht,  and 
the  tables  and  several  of  thG  diagrams  were  prepared  by  Mr.  Schlecht. 
The  object  of  the  measurements  made  at  these  stations  was  to 
determine  primarily  the  run-off  from  the  various  drainage  basins 
and  the  availability  of  the  streams  as  sources  of  additional  supply 
of  water  for  New  York  City.  The  results  of  the  measurements, 
together  with  the  heights  of  water  in  the  river  on  each  day,  have 
been  published  in  Water-Supply  Paper  No.  65.  Incidentally  it  was 
thought  best  to  make  observations  as  to  the  point  of  mean  velocity 
in  each  of  these  streams  for  use  in  future  measurements  on  the 
same  rivers,  as  well  as  for  general  information  as  to  1  he  most  desirable 
method  of  making  current-meter  measurements  on  rivers  in  general. 
In  making  measurements  of  rivers  of  this  character  it  has  been  the 
custom  of  the  Hydrographic  Division  of  the  United  States  Geological 
Survey  to  divide  the  cross  section  into  partial  areas  of  regular 
width,  say  5  or  10  feet,  and  to  determine  the  velocity  in  each  of  these 
small  areas  by  holding  the  meter  at  a  point  six-tenths  of  the  total 
depth  below  the  surface.  The  velocity  obtained  al  this  point  was 
assumed  to  be  the  mean  velocity  in  the  small  area  in  which  the  meter 
was  used.  It  was  realized  that  this  relation  would  not  hold  true  in 
all  streams,  but  in  rivers  with  the  general  characteristics  of  those 
under  discussion  it  was  considered  that  no  serious  error  would  result 
from  this  assumption.  The  data  in  the  following  pages  were  collected 
in  order  to  check  the  above  assumption  or  to  enable  the  hydrographer 
to  determine  by  a  [joint  measurement  the  velocity  al  some  other  depth 
which  might  be  considered  the  mean  in  the  channel.  Each  of  the  sta- 
tions established  will  now  be  briefly  described.  The  drainage  basins 
were  described  in  detail  in  Water-Supply  Paper  No.  65. 

CATSKILL  CREEK  AT  SOUTH  CAIRO,  N.  Y. 

The  gaging  stat ion  is  located  al  the  highway  bridge  in  the  village 
of  South  C  airo,  a  view  of  w  hich  is  shown  on  PI.  III.    The  total  span 


28 


FLOW   OF  RIVERS  NEAR  NEW    YORK  CITY. 


[so.  76. 


of  the  bridge  is  L94.5  feet  between  abutments,  the  faces  of  which  are 
vertical.  The  stream  bed  is  of  earth  for  25  feet  from  the  right  abut- 
ment. Ai  this  poinl  the  bluestone  rock  ledge  outcrops,  covered  with 
patches  of  loose  shingle  and  shifting  gravel,  while  the  left  side  of  the 
channel  is  covered  with  small  gravel.  The  entire  flow  of  the  stream 
at  all  stages  passes  under  this  bridge.  High-water  marks  at  the  bridge 
indicate  a  maximum  elevation  of  17.5  feet  on  the  gage.  The  stage  of 
the  stream  is  observed  each  morning  and  evening  by  the  local  gage 
reader,  and  current-meter  measurements  are  made  at  intervals  by  the 
resident  hyd  rographer. 

ESOPUS  CREEK  AT  KINGSTON,  N.  Y. 

This  gaging  station  was  established  at  Washington  avenue  bridge 
in  Kingston  July  5,  1901,  a  view  of  which  is  shown  in  PI.  IV.  This 
bridge  has  a  clear  span  of  100.6  feet  between  abutments,  which  are 
nearly  vertical.  In  addition  there  is  on  the  left  side  a  channel  19  feet 
in  width  through  which  water  passes  at  high  stages  of  the  river.  Gage 
readings  are  made  here  each  morning  and  evening.  The  bed  is  covered 
with  small  stone  over  part  of  the  channel,  the  rest  of  the  bed  being 
made  up  of  sand,  silt,  and  small  gravel. 

WALLKILL  RIVER  AT  NEW  PALTZ,  N.  Y. 

A  gaging  station  is  situated  at  the  New  Paltz  highway  bridge,  a  view 
of  which  is  given  in  PI.  V.  The  bridge  is  a  span  of  146.6  feet  between 
the  vertical  faces  of  the  masonry  abutments.  The  entire  flow  passes 
under  this  bridge  except  in  extreme  freshets,  when  the  left  bank  is 
overflowed. 

The  bed  of  the  river  is  for  the  most  part  smooth,  and  composed  of 
sand  and  silt. 

RONDOUT  CREEK  AT  ROSENDALE,  N,  Y. 

A  gaging  station  wa  s  established  at  the  highway  bridge  at  Rosendale, 
:i  miles  above  the  junction  of  the  WaHkill,  July  G,  1001.  The  bridge 
is  a  single  span  of  136  feet,  and  is  shown  in  PI.  VI.  The  bed  of  the 
channel  is  rock  with  bowlders  for  40  feet  from  righl  bank,  the  rest  of 
the  bed  being  covered  with  broken  rock  from  6  inches  to  1  foot  in 
diameter.  The  entire  flow,  aside  from  the  diversion  to  the  Delaware 
and  Hudson  ('anal,  passes  under  the  bridge  at  all  stages. 

PISHKILL  CREEK   AT  (JLENHAM,  N.  V. 

A  gaging  station  is  located  at  the  Newburg,  Dutchess  and  Con- 
necticut Railroad  bridge,  in  Glenham.  It  was  established  July  S, 
L901.    The  bridge  consists  of  the  main  central  span  with  twoauxil- 


PH  BSBBI  I 


VERTICAL  VELOCITY   Cl'K\  E8. 


iary  overflow  channels  at  the  ends,  the  length  of  span  being  as  fol- 
lows: Left  overflow,  si al ion  zero  to  22.5;  main  span,  station  27. 5  1o 
station  122;  right  overflow,  station  1'2~  to  station  L49.  The  1  >< *<  1  of 
the* main  channel  is  earth  and  gravel;  that  of  the  overflow  channels 
is  broken  stone. 

TENMILE  RIVER  BELOW  DOVER  PLAINS,  N.  Y. 

A  gaging  station  was  established  September  In,  1001,  at  Tabor's 
bridge,  which  crosses  Tenmile  River  about  2,000  feet  below  the  point 
of  inflow  of  Swamp  River.  The  gaging  station  is  situated  about  2 
miles  below  Dover  Plains  Village.  Tabor's  bridge  consists  of  a  single 
span,  85  feet  between  abutments.  The  bridge  stands  square  across 
the  stream,  the  bed  of  which  is  sand  and  gravel.  The  entire  flow 
passes  between  the  abutments  of  this  bridge,  except  at  the  lime  of 
extreme  high  water,  which  occurs  nearly  every  spring  when  the  river 
overflows  its  banks,  and  some  water  passes  around  one  end  of  the 
bridge 

HOTJSATONIC  RIVER  AT  GAYLORDSVILLE,  CONN. 

A  gaging  station  was  established  at  Gaylordsville,  Conn.,  October 
1900.  The  station  is  situated  3  miles  east  of  the  New  York  State 
line  and  2  miles  below  the  month  of  Tenmile  River.  Owing  to  the 
unfavorable  conditions  under  the  bridge,  the  discharge  measurements 
are  made  from  a  cable  Of  200  feet  span  placed  across  the  stream  l1, 
miles  below  the#bridge.  A  view  of  the  river  at  this  point  is  shown  in 
PI.  VII.  The  cable  is  supported  on  the  right  bank  by  timber  shears 
25  feet  high  and  is  anchored  to  a  large  buried  rock.  On  the  left- 
bank  a  sycamore  tree  serves  as  a  support  for  the  cable,  which  is 
anchored  to  the  base  of  a  large  oak. 

DISCUSSION  OF  TABLES. 

In  the  tables  that  are  given  in  the  following  pages  the  measure- 
ments recorded  were  taken  at  the  time  of  the  regular  gagings  of  the 
rivers,  and  with  the  same  degree  of  accuracy  with  which  current- 
meter  measurements  have  been  made  upon  these  streams.  <  >nly  one 
instrument  was  used  at  one  time,  the  velocity  being  taken  al  the 
various  points  in  regular  order  vertically,  usually  at  intervals  of  one- 
half  foot.  When  other  space  intervals  were  used  it  is  shown  in  the 
tables. 

In  PI.  VIII  is  shown  the  variation  in  the  velocity  of  Wallkill  River 
at  New  Paltz.  The  dotted  lines  are  lines  of  equal  velocities  and  are 
determined  by  observations  of  velocity  at  regular  intervals  throughout 


30 


FLOW   OF  RIVEBS   NEAR  NEW    YORK  CITY, 


[SQ,?6. 


the  erbss  section.  The  line  marked  "  mean  velocitjnFbr  each  section" 
shows  the  deptlval  which  maybe  found  the  filamentof  mean  velocity. 
Near  the  right  bank  there  is  slack  water  and  some  return  current, 
which  accounts  for  the  peculiar  position  of  the  curve,  and  the  fad 
that  there  are  two  lines  of  mean  velocity.  This  condition  would  not 
usually  occur  at  a  gaging  stat  ion. 

At  the  bottom  of  PI.  VIII  arc  lines  showing  the  velocity  ai  various 
depths,  as  1  foot  ,  2  feet,  etc.,  across  the  river  section.  The  effecl  of 
the  ledge  of  rocks  is  clearly  shown  in  Ihe  plate. 

A  small  Price  current  meter  was  used,  and  was  in  each  case  sus- 
pended from  a  bridge  and  hung  freely  in  the  water.  The  meter  was 
held  fifty  seconds  at  one  point  to  determine  the  velocity,  and  in 
each  case  the  first  reading  was  checked  by  a  second, and  if  there  was 
a  discrepancy  a  third  reading  was  taken.  The  results  were  plotted 
upon  Cross-sec1  ion  paper,  the  depl  hs  as  ordinates  and  the  velocities  as 
abscissas,  and  a  smooth  curve  drawn  through  the  points,  so  that  in 
case  t  here  was  an  error  of  sufficient  magnil  ude  to  affect  the  final  results 
if  would  be  found  when  the  curve  was  plotted.  Before  the  work  was 
commenced,  and  after  the  completion  of  these  curves,  the  meter  was 
rated  and  showed  very  slight  change  in  its  readings.  The  gage  height 
was  read  at  Ihe  beginning  of  each  measurement  and  at  its  complel  ion. 
and  in  general  no  change  of  stage  of  the  stream  during  the  measure- 
ment was  noted. 

In  Table  I  the  date  of  each  measurement  is  given  at  Ihe  head  of  the 
column,  then  the  point  of  measurement — that  is,  the  distance  in  feel 
from  the  initial  point  of  soundings  which  had  been  previously  estab- 
lished and  marked  permanently  on  the  bridge.  Next  is  given  the 
gage  height  at  the  time  the  velocities  were  measured  and  the  depth  of 
water  at  the  point  of  measurement  at  the  time  of  making  1  he  measure- 
ment. The  character  of  Ihe  bed  of  the  river  and  the  force  and  direc- 
tion of  the  wind  are  also  given.  The  depths,  as  given  in  the  alternate 
columns,  were  measured  by  a  wire  attached  to  the  meter  and  a  tape. 
The  column  headed  "Velocities"  gives  the  actual  observed  velocity 
in  feet  per  second  at  each  observation. 

Table  II  is  computed  from  Table  I,  the  observal  ions  being  the  same, 
but  the  velocities  being  given  at  regular  depths  as  shown  in  percent- 
ages of  the  whole  in  the  first  column.  The  velocities  as  shown  in  the 
columns  of  this  table  were  found  from  the  plotted  vertical  velocity 
curves  based  upon  t  he  figures  in  Table  1,  the  velocities  .it  each  depth 
being  taken  by  scale  directly  from  tin;  curve.  The  sum  of  the  veloci- 
ties in  each  column  of  Table  II  divided  by  10  gives  the  mean  velocity 
in  t  hat  sect  ion,  and  is  the  quantity  thai  should  be  obtained  by  a  single 
meter  observation  at  a  point  in  the  sect  ion  which  represents  the  point 
of  mean  velocity.  For  comparison,  the  velocity  as  actually  found  at 
six-tenths  of  the  depth  is  given  at  the  bottom  of  Table  II,  from  which 


I'I(K>SKV  | 


VERTICAL  VELOCITY  CURVES. 


31 


it  will  at  once  be  seen  thai  the  error  in  measuring  the  velocity  at 
six-tenths  depth  is  in  general  only  slighl  on  a  stream  of  the  general 
character  of  t  he  Ksopns. 

Tables  III,  V,  VII,  IX,  XI,  and  XIII  show  1  he  results  ofthemeas- 
urements  on  the  Rondout,  Wallkill,  Catskill,  Fishkill,  Tenniile,  and 
Housatonic,  respectively;  Tables  IV,  VI,  VIII,  X,  XI  I,  ami  XlVshow 
the  data  obtained  from  the  preceding  tables,  ami  were  derived  by  the 
same  met  hod  as  Table  II  from  Table  I. 


32 


FLOW   OF   RIVERS  NEAR  NEW   York  CITY. 


[NO.  76. 


■*»  fe  ^  SB  3K  8  S  S  £  13  g  |3  §8  5 



•q}da(3 

Feet. 
0.5 
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3.4 
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4.5 
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Sept.  21, 

90. 

4.78. 

6.6. 

Silt  and 
gravel. 

Gentle. 

Upstream. 

•A^IOOpA 

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0. 86 
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.95 
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80. 
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None. 

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Sept.  (i. 
40. 
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None. 

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PRESSEY.] 


VERTICAL  VELOCITY  CURVES. 


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34 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY. 


[no.  70. 


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VERTICAL  VELOCITY  CURVES. 


Dec.  21. 
70. 
7.60. 

Bowlders. 

Gentle. 

Up- 
stream. 

Fee* 
per 
sec. 

1.94 

1.96 

1.89 

1.77 

1.70 

1.50 

.80 

.62 

'mdoQ 

iC    iC    ifl   «5   00    K5    if!  a 

1*1  ee  ih  «*  ee  p5A  ih  *a  us 

— 

; — 

Nov.  26. 
65. 
7.21. 
6. 6. 
Bowlders. 
None. 

Fee* 
per 
sec. 

7.76 

1.71 

1.70 

1.69 

1.70 

1.30 

1.04 

U^dOQ 

Ff. 
0.5 
1.5 
2.5 
3.5 
4.0 
5.0 
4.0 

Nov.  16. 

70. 

6. 55. 

'      5. 6. 

Bowlders. 

Strong. 

Down- 
stream. 

•Xjl.)Ol9A 

Feel 
per 
sec. 

0.65 

.65 

.60 

.56 

.50 

.32 

.20 

— 

- 

Ui(l,)(j 

Ft. 
0.5 
1.5 
2.5 
3:4 
3.5 
4.5 
5.0 

Nov.  7. 
80. 

6.42.  . 
6. 2. 
Bowlders. 
Gentle. 

"AV110OT9  A 

Feet 
per 
sec. 

0.48 

.46 

.45 

.43 

.45 

.32 

.20 

q;doQ 

Ijj  ic  >^  >c  »n  »-  o  eo 

1*1  C>  r-5  *i  ©9  ©9*  tfj 

Oct.  18. 

65. 

7.03. 

6. 3. 

Bowlders. 

Strong. 

Down- 
stream. 

1 

X^Do^e^ 

per 
sec. 

1.41 

1.42 

1.42 

1.37 

1.85 

1.22 

1.07 

.82 

5.2 

- 

u^dftQ 

O         rl  C*  09  09         id  U9 

Oct.  11. 

;  85. 

6. 47. 

6. 2. 

Bowlders. 

Gentle. 

Up- 
stream. 

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te,  Si5*  © 

q;deQ 

hJ    00    OC    00    I-    I-    J-  b- 
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Oct.  11. 
75. 
6. 47. 
5. 6. 
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Gentle. 

"A"  HOOT  9  A 

Sfcg  8  S  !5  S*  3  8  « 

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Oct.  11. 

65. 

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5. 6. 

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Up- 
stream. 

'  AVlIOOT9  A 

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IQ    >"    i~    ■*  ID   IS  H 

^  d  H  «  09  00  >~ 

«        .  ©  »  a  a 

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sec. 

0. 51 

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.30 

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2. 0 
3.0 
3.4 
4.0 
5.1 

S  a  S  l-  f  1  I « 

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sec. 

1.58 

1.52 

1.49 

1.44 

1.19 

— 

4  -""{^ 

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SI    N   «   N   N  ! 
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Aug.  8 . 
45. 
7. 15. 
5. 2. 
Bowlders. 
None. 

■  A^uo^9A. 

Feet 
per 
sec. 

1 . 29 

1.40 

1.42 

1.44 

1.40 

1.14 

.89 

UldecL 

^  N  N  N  1>  N  «  N 

&h  d    '  ri  h  ei  m  ■* 

Aug.  8. 
105. 
7.50. 
5. 9. 
Bowlders. 
None. 

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lUd9Q 

SI    SI   SI   S)    SI   SI  '• 
*(  O  ri  S)  CO  -HI  lO  j 

Aug.  8. 
90. 
7.50. 
7.2. 
Bowlders. 
None. 

•A"^i.x)X9A 

Feet 
pet- 
sec. 

1.70 

1.00 

1.65 

1.54 

1.83 

1.29 

1.24 

1.00 

.98 

.86 

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36 


FLOW  OF  RIVERS  NEAR  NEW   YORK  CITY. 


[no.  76. 


i2  g  g  f*:  g  §  SS  i5  in  g 


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PRESSEY.] 


VERTICAL  VELOCITY  CURVES. 


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38 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY. 


[NO.  76. 


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FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY 


[no.  76. 


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VERTICAL  VELOCITY  CUBVES. 


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42 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY, 


[no,  76. 


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pressey]  VERTICAL  VELOCITY  CUEVES.  43 

Table  XL — Velocities  in  vertical  sections  on  Tciunilr  River  at  Dover  Plains. 


Date  

Point  of  measure- 
ment   

Gage  height  

Depth  

Bed  of  creek  

Wind   


Direction   Downstream. 


Oct.  15. 

55. 
7.19. 

6.8. 
Sand. 
Fresh. 


Oct.  20. 

25. 
5.01. 

4.6. 
Sand. 
None. 


Oct.  20 


ViH. 
4.8 
Sand. 
None 


Nov.  LI. 

25. 
4.75. 

4.4. 
Sand. 
N  »nc. 


Depth 


Feet. 
0.5 
1.5 
2.5 
3.5 
4.1 
4.4 
5. 3 
6.3 


Veloc- 
ity. 


Depth 


Ft.  per 
sec. 

2.43 

2.38  ; 

2.31 

2.19 

2.17 

2.09 

2.00 

1.84 


Feet. 
0.3 
.8 
1.3 
1.8 
2.3 
2.8 
3.3 
4.1 


Veloc- 
ity. 


Ft.  per 

sec. 

l.io 
1.07 
LOO 

.92 
.90 


Depth 


Feet. 
0.5 
1.5 
2.5 
2.9 
3.5 
4.3 


Vela 

ity 


Ft.  per 
sec. 

1.00 

.95 

.93 

.92 

.'.to 


Depth 


Feet. 
0.4 
.9 
1.4 
2.0 
2.6 
3.0 
3.5 
3.9 


Veloc- 
ity. 


Ft.  per 
sec. 

0.90 


.70 
.67 
.61 
.55 
.50 


Nov.  22. 

25. 
4.70. 
4.2. 
Sand. 
Gentle. 
1 ).  iwnstream. 


Depth 


Feet. 
0. 3 
.8 
1.5 
2.0 
2.5 
3.0 
3.5 
3.7 


Veloc- 
ity. 


Ft.per 
sec. 

0.84 

.84 

.73 

.75 

.67 

.56 

.  55 


Table  XII. — Velocities  at  regular  intervals  in  vertical  sections  on  Tenmile  River 
at  Dover  Plains. .deduced  from  data  in  Table  XI. 

[Velocities  in  feet  per  second.] 


Depths  in  parts  of  total. 


0.05  

.15   

.25  9 

.35   

.45  

.55  

.65.  

.75   

.85   

.95  

Mean  


Oct.  15 


<  let.  20 


2.  44 
2.42 
2.36 
2.30 
2.23 
2. 16 
2.09 
2.02 
1.95 
1.83 


1.08 
1.06 
1.03 
.98 
.93 
.87 
.81 
.73 


2. 18 


2. 13 


84 


Oct.  20. 


0.99 
.!«» 
.98 
.97 
.95 
.93 
.91 


.91 


.92 


Nov.  11. 


0.89 
.80 
.83 
.79 
.  75 
.70 
.64 
.58 
.52 
.44 


.70 
.f,7 


Nov.  22. 


0.84 
.84 
.82 
.78 
.74 
.70 
.65 
.59 
.51 
.43 


44 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY. 


[no.  76. 


Table  XIII. — Velocities  in  vertical  sections  on  Housatonic  River  at  Gaylordsville. 


Date  

Point  of  measurement 

Gage  height   

Depth   

Bed  of  creek    

Wind   

Direction  

r  

Aug.  8. 
GO. 
3.50. 
3.8. 
Gravel. 
None. 

Oct.  29. 
60. 
4.05. 
4.8. 
Gravel. 
None. 

Nov.  13. 
60. 
4.82. 
6.2. 
Gravel. 
Very  strong. 
Downstream. 

Nov.  23. 
60. 
4. 11. 
4.8. 
Gravel. 
Gentle. 
L'p^tream. 

Depth. 

Velocity. 

Depth. 

Velocity. 

Depth. 

Velocity. 

Depth 

Velocity. 

Ft.  per 

Ft.  pet- 

Ft.  per 

Ft.  per 

Feet. 

sec. 

Feet. 

sec. 

Feet. 

sec. 

Feet. 

sec. 

0.20 

2. 19 

0.5 

2.98 

0. 5 

3.84 

0. 5 

3. 03 

.30 

2.2*3 

1.5 

2.90 

1.5 

3. 93 

1.5 

2. 92 

.8 

2.25 

2.5 

2.85 

2.5 

3. 84 

2.5 

2. 81 

1.3 

2.14 

2.9 

2.68 

3.5 

3.50 

2.9 

2. 61 

1.8 

2. 07 

3.5 

2.39 

3.7 

3. 44 

3.5 

2.38 

2.3 

2. 05 

4.3 

1.92 

4.5 

3. 23 

4.3 

1.90 

2.8 

1.72 

5.6 

2.50 

CO 
CO 

1.35 

Table  XIV. — Velocities  at  regular  intervals  in  vertical  sections  on  Housatonic 
River  at  Gaylordsville.  deduced  from  data  in  Table  XIII. 

[Velocities  in  feet  per  second.] 


0.05. 
.15. 
.25 
.35 
.45. 

.65 
.  75 

.85. 


.60 


Depths  in  parts  of  total. 


Mean 


Aug.  8. 

Oct.  29. 

Nov.  13. 

Nov.  23. 

2.21 

3.00 

3.89 

3.02 

2.23 

2. 97 

3.90 

3.01 

2.21 

2.94 

3.91 

3.00 

2.17 

2-90 

3.89 

2.94 

2. 10 

2.85 

3.79 

2.85 

2.02 

2. 77 

3. 60 

2.  72 

1.85 

2.57 

3.38 

2. 52 

1.66 

2.35 

3.11 

2.34 

,.4.-, 

2. 10 

2.79 

2. 10 

1.20 

1.75 

2.04 

1.80 

1.91 

2.62 

'  3.  43 

2.63 

1.94 

2.67 

3.49 

2.62 

For  the  purpose  of  comparison  a  mean  curve  for  each  of  the  streams 
has  been  determined  by  taking  the  mean  of  all  the  velocities  shown  in 
eaeli  of  Tables  II,  IV,  VI,  VIII,  X,  XII,  and  XIV.  To  facilitate  com- 
parison, the  data  for  these  mean  curves  have  been  expressed  in  per- 
centages of  the  mean  velocity  in  a  vertical  section,  and  arc  shown  in 
Table  XV,  the  total  number  of  curves  being  78.  By  this  arrangement  a 
figure  in  the  column  greater  than  100  shows  a  velocity  greater  than  the 
mean  in  the  vertical  section  being  considered,  and  a  velocity  less  than 
100  shows  a  velocity  less  than  the  mean.  The  mean  curves  have  been 
plotted  in  fig.  2.  It  will  be  seen  from  these  curves  that  the  general 
character  of  the  vertical  velocity  curves  is  much  the  same  in  each 


PRESSEY.] 


VERTICAL  VELOCITY  CURVES. 


45 


case,  showing  fairly  conclusively  lliai  we  may  prophesy  as  to  the 
general  character  of  the  vertical  velocity  curve  in  natural  streams 
with  steep  banks  and  from  smooth  to  moderately  rough  bottoms,  and 
depths  of  from  3  to  8  feet.  It  will  be  noted  that  the  ratio  of  1  he  mean 
velocity  to  the  surface  velocity  varies  from  92  per  cent  on  the  Fishk ill 
to  82  per  cent  on  the  Catskill,  and  that  the  maximum  velocity  of  1  hese 
streams  varies  from  13  to  25  per  cent  greater  than  the  mean,  and  that 
at  no  point  do  all  of  the  curves  fall  so  closely  together  as  at  six-tent  lis 
depth.  At  that  point  the  greatest  variation  from  the  mean  is  2\  per 
cent.  This  shows  that  the  measurements  made  at  six-tenths  depth 
were  subject  to  less  variation  than  those  made  at  any  other  point, 
and  that  in  general,  on  streams  of  the  character  here  represented,  a 
measurement  made  at  that  point  would  represent  approximately  the 
mean  velocity  in  the  section.  It  will  be  noted  that  none  of  the  curves 
cross  the  line  of  mean  velocity  at  a  greater  depth  than  0.03,  nor  at  a 
less  depth  than  0.5G,  showing  that  the  point  of  mean  velocity  on  these 
streams  lies  between  these  two  depths. 


Table  XV. — Averages  of  velocity  curves  expressed  in  terms  of  mean  velocity  in  a 
vertical  section  {represented  as  10"). 


Stream  

No.  of  velocity 
curves. 

Bed  of  stream... 
Mean  depth  

Esopus. 

Ron- 
dout. 

Wall- 
kill. 

Cats- 
kill. 

Fish- 
kill. 

Ten- 
mile. 

Housa- 
fonic. 

Average 
of  all  the 
streams. 

12. 

8. 

13. 

9- 

13. 

5. 

4. 

78. 

Small 
gravel. 

f 

Bowl- 
ders. 

Aver- 
age. 

Bowl- 
ders. 

Silt. 

Small  Large 
gravel  gravel. 

and 

rock 
ledge. 

Sand. 

Gravol. 

Various. 

6.5. 

4.7. 

5.8. 

6.     |  7.3. 

3.2.    |  3.7. 

5. 

4.9. 

5.07. 

Depth  below 
surface  in 
parts  of  total: 

0.05  

.15  

.25  

.35  

.55  

.65   

.75  

.85  

35 

Mean  

7\  .90  

118.6 
120.8 
118.9 
115.0 
109.3 
102.3 
94.4 
85. 5 
74.9 
60.3 

115.9 
116.6 
115.5 
112.7 
109.4 
104.8 
98.6 
89.7 
77.8 
59.0 

117.3 
118.8 
117.3 
113.9 
109.3 
103.5 
91).  4 
87.5 
76.3 
59.7 

117.9 
119.0 
11S.  5 
115.9 
111.7 
105.9 
97.2 
86.3 
72.8 
54.2 

100.  Q 

119.7 
118.4 
115.4 
111.6 
107.4 
102.5 
<J6.3 
89.0 
78.0 
61.1 

124.7 
124.8 
121.8 
116.5 
109.7 
101.5 
92.5 
81.9 
70.7 
55.9 

110.  7 
113.7 
113.4 
111.3 
108.2 
104.0 
98.3 
91.0 
81.2 
68.2 

116.  S 
135. 6 
112. 7 
109.0 
104.9 
100.4 
95. 5 
89.9 

as.  3 

71.9 

114.4 
114.3 
113.9 
112.4 
109.5 
105.0 
97. 4 
89.3 
79.7 
64.  1 

117.0 
117.9 
110.3 
113.2 
109.0 
103.6 
96.5 
87.9 
77.2 
61.4 

100.0 

100.0 

100.0 
100.2 

100.0 

100.0 

100.0 

100.0 

100.0 

100.0 

98.9 

101.7 

101.8 

99.6 

97.2 

lni  t 

98.1 

101.2 

100. 26 

In  Table  XV,  under  the  heading  ''Average  of  all  the  streams,"  the 
mean  velocity  of  each  depth  given  in  the  table  is  shown,  and  the  curve 
representing  this  mean  vertical  velocity  curve  is  platted  in  fig.  as  a 
solid  line.  This  curve  represents  the  mean  of  78  vertical  velocity 
curves,  the  mean  of  the  vertical  velocity  curves  platted  in  fig.  2. 


46 


FLOW  OF  RIVFKS  NEAR  NEW  YORK  CITY. 


[NO.  76. 


It  will  be  noted  in  this  curve  that  the  relation  between  the  mean 
velocity  and  the  surface  velocity  is  87;  that  the  maximum  velocity  is 
18  per  cent  greater  than  the  mean,  and  that  the  point  of  mean  velocity 
is  almost  exactly  at  six-tenths  depth,  the  variation,  as  shown  in  the 
last  column  of  Table  XV,  being  about  one-fourth  of  1  per  cent.  This 
shows  clearly  that  a  measurement  made  at  six-tenths  of  the  depth  of 
a  stream  having  the  general  characteristics  of  those  considered  will 
in  general  represent  closely  the  mean  velocity  in  that  section. 

To  show  the  relation  between  the  velocity  at  mid  depth  and  the 
mean  velocity  in  a  vertical  section  Table  XVI  has  been  compiled 
from  Table  XV.  From  this  table  it  will  be  seen  that,  upon  streams 
like  these  being  considered,  if  the  mid  depth  is  known,  the  mean 
velocity  in  the  vertical  section  may  be  found  by  apptying  a  coefficient 
of  0.04. 


Table  XVI. 


Relation  between  velocity  at  mid  depth  to  mean  velocity  in  a  vertical 
section. 


Stream. 


Rondout 
Wallkill___ 
Catskill 
Fishkill  . 
Temnile- .  . 
Honsatonic 


Velocity  at 
mid  depth 

expressed  in 
percentage 

of  the  mean. 


U)6.4 
108.8 
104.9 
105. 6 
106.1 
102.  6 
107.2 


Ayerage. 


106.3 


Coefficient  to 
be  applied  to 
velocity  at 
mid  depth  to 
obtain  mean 
velocity. 


0.94 
.92 
.95 
.94 
.94 
.97 
.93 


94 


Humphreys's  and  Abbott's  observations  on  the  Mississippi  River 
gave  a  coefficient  of  0.98,  while  Ellis,  on  the  Connecticut,  found  0.!>4, 
and  Wheeler  and  Lynch,  on  the  Merrimac  flume,  found  0.95.  It  will 
be  seen  that  there  is  a  variation  of  5  per  cent  on  the  streams  being 
considered  in  this  paper,  and  that  the  results  of  Humphreys  and 
Abbott  on  the  Mississippi  and  Ellis  on  the  Connecticut  vary  from 
each  other  by  4  per  cent,  alt  hough  the  rivers  are  froth  large  and  have 
somewhat  t  he  same  characteristics.  In  view  of  these  facts,  it  seems 
that  it  is  somewhat  better  to  measure  the  velocity  at  the  point  of  mean 
velocity  than  to  measure  the  velocity  at  mean  depth  and  apply  a 
coefficient. 

It  is  very  evident  that  the  character  of  the  bed  will  affect  1<>  some 
extent  the  form  of  the  vertical  velocity  curve.  A  rough  bed  would 
be  expected  to  retard  the  velocity  near  the  bottom  of  the  stream. 
None  of  the  streams  under  investigation  may  be  considered  to  have 
extremely  rough  beds,  but  by  comparison  the  beds  of  Rondout  Creek 


PKKSSEY.] 


VERTICAL  VELOCITY  CURVES. 


47 


and  Housatonic  River  may  be  said  to  be  rough,  while  those  of  the 
Wallkill  River  and  Tenmile  Greek  are  smooth  al  the  point  of  measure- 
ment. Part  of  the  bed  of  the  Esopus  is  rough  and  pari  smooth.  In 
order  to  determine  the  effect  of  the  variation  in  the  bods  on  the  flow, 
the  results  in  Table  XV  have  been  classified  in  Table  XVII  into 
streams  with  rough  and  smooth  bottoms,  the  Rondout,  Housatonic, 
and  part  of  the  curves  on  the  Esopus  being  in  the  firsl  column,  and 
the  Wallkill,  Tenmile,  and  remaining  observations  on  the  Esopus  in 
the  second.  The  results  shown  in  these  two  columns  have  been  plotted 
in  fig.  3. 

It  will  be  seen  that  the  rough  bed  causes  a  drag  at  the  lower  end  of 
the  vertical  velocity  curve,  due  largely  to  eddies  formed  at  the  bot- 
tom of  the  stream.  This  retardation  of  the  water  near  the  bed  of 
the  stream  causes  the  point  of  mean  velocity  in  the  vertical  section 
to  rise,  and  a  measurement  of  velocity  made  at  0.60  depth  will  there- 
fore be  too  small.  With  a  smooth  bed  a  measurement  made  at  0.60 
depth  will,  in  general,  be  too  large,  the  filament  of  mean  velocit}'  being 
nearer  the  surface.  In  other  words,  in  making  a  measurement  of 
mean  velocity  in  a  vertical  section  the  meter  should,  in  general,  be 
suspended  above  0.60  depth  in  streams  of  rough  bed  and  below  0.60 
depth  in  streams  of  smooth  bed.  In  the  rivers  here  considered  the 
variation  of  roughness  of  beds  is  so  small  in  the  different,  streams 
that  the  error  in  assuming  the  velocity  at  0.60  depth  to  be  the  mean 
velocity  in  the  vertical  section  would  not  be  great,  but  in  streams  of 
very  rough  beds  the  variation  would  be  more  marked. 


Table  XVII.—  Relation 

between  velocities  in  vertical 

sections  with 

smooth  ( Did 

rough  bottoms. 

1  >t'pth  below  su 

rface— in  parts  of  total. 

Smooth  bot- 
tom: 
Esopus,  Wull 
kill,  Tenmile. 

Rough  bot- 
tom: 
Rondout,  Hou- 
satonic. 

Velocity  in  per- 
rentage  of  tli r 
mean. 

Velocity  in  per- 
centage of  the 
mean. 

0.05    

ns.r 

116.2 

.15.  

118.8 

117.0 

.25   

116.2 

116.0 

.35   

112.4 

113. 8 

.45.  

107  Ji 

110.3 

.55.   

L02.0 

105.3 

.65   

95.  4 

07.  7 

.75..   

87.8 

88.3 

.85   

78.1 

70.5 

.95  

63.0 

58.  9 

Mean   

100.0 

100.0 

.60  

99.0 

101.6 

48 


FLOW  OF  EIVERS  NEAR  NEW  YORK  CITY. 


[no.  76. 


FLOW  OF  RIVERS  UNDER  ICE,  SMOOTH  AND  U3S*BOKEN 

COVER. 

It  is  frequently  desirable  to  measure  the  flow  of  rivers  and  canals 
when  they  are  covered  with  a  coating  of  ice.  It  is  quite  clear  that 
the  same  relations  in  various  parts  of  the  channel  do  not  hold  good 
when  the  channel  is  covered  with  ice  as  when  the  surface  is  open. 
The  friction  between  the  water  and  the  ice  retards  the  surface  veloc- 
ity, and  it  is  possible  that  in  a  few  cases  the  river  ma}T  flow  under  a 
head  if  the  ice  cake  is  heavy  and  held  firmly  in  position.  In  making 
measurements  of  the  flow  of  a  river  when  frozen  over,  floats  can  not 
be  used,  and  in  general  a  current  meter  is  the  most  serviceable 
instrument. 

Distance  from  abutment  in  feet— 


<>        10       20       30       40       50       00       70       80       90      100     110      120      130  140 


Fig.  4. — Cross  section  of  Wallkill  River  at  New  Paltz,  showing  ice  cover  and  curves  of  equal 
velocity  in  river  channel.  (Note.— Measurements  taken  January  23, 1902;  117  measurements  of 
velocity  being  made  with  the  current  meter;  mean  velocity,  3.23  feet  per  second;  discharge, 
6,063  second-feet.   The  dotted  line  shows  the  position  of  mean  velocity  in  the  vertical  section.) 


During  the  winter  of  1901-2  observations  to  determine  the  change 
of  velocity  in  a  vertical  plane  below  the  ice  were  made  on  Wallkill 
River,  and  Esopus,  Rondout,  and  Catskill  creeks,  and  the  data  col- 
lected arc  presented  in  the  following  tables/'  The  observations  were 
made  by  cutting  holes  through  t  lie  ice  large  enough  t  o  admit  a  current 
meter.  The  thickness  of  the  ice  in  each  case  is  given  in  the  table, 
and  the  fact  that  the  water  rose  in  most  cases  to  a  point  about  flush 
with  the  surface  of  the  ice  shows  that  there  was  some  pressure  upon 
the  (lowing  stream.  It  may  be  of  interest  in  passing  to  note  the  dis- 
tribution of  the  velocity  in  the  cross  section,  as  shown  in  fig.  4,  the 
result  of  the  gagings  made  on  the  Wallkill  River  at  the  New  Paltz 
gaging  station,  January  23,  1902.  The  total  area  of  the  water  sec- 
tion was  1,880  square  feet,  the  mean  velocity  3.23,  and  the  discharge 
0,00.'}  second-feet.    One  hundred  and  seventeen  measurements  were 


aTheso  observations  were  made  incidental  to  the  discharge  measurements  of  the  streams. 


PR  ESSE  Y.] 


FLOW  OF  KIVEKS   UNDER  ICE. 


49 


made  with  the  currenl  meter,  and  the  points  arc  plaited  in  the  figure, 
the  velocity  in  feel  per  second  being  noted  beside  each  point.  The 
mean  velocity  in  feel  per  second  in  a  vertical  section  is  shown  by  the 
figures  across  the  top  of  the  section.  A  dotted  Line  showing  the  posi- 
tion of  the  mean  velocity  in  the  vertical  sections  has  been  drawn  on 
the  cross  section.  It  will  be  seen  that  the  maximum  velocity  occurs 
near  the  center  of  the  channel,  and  at  about  mid  depth,  and  that 
the  effect  of  the  ice  covering  is  to  form  a  covered  flume,  the  curves 
of  equal  velocity  being  much  the  same  as  have  been  plotted  occasion- 
ally for  such  flumes.  The  water  just  below  the  ice  is  so  retarded  that 
there  are  two  points  of  mean  velocity,  as  shown  in  figs.  4  and  5. 

In  the  following  tables  are  given  the  results  of  measurements  made 
in  vertical  sections  upon  the  above-mentioned  rivers.  These  measure- 
ments were  made  with  a  single  meter,  the  velocities  being  taken  at 
intervals  of  from  1  to  2  feet,  these  distances  being  shown  in  each  case 
in  the  table.  Tables  XVIII,  XX,  XXII,  XXIV,  and  XXVI  show  the 
velocities  as  determined  by  actual  measurements.  At  the  head  of  the 
table  are  given  the  date,  distance  from  initial  point  of  sounding,  gage 
height  at  the  time  of  measurement,  total  depth  of  the  river  (includ- 
ing ice),  tlie  thickness  of  ice,  and  the  depth  of  water  under  the  ice. 
In  every  case  the  depth,  as  given  in  the  body  of  the  table,  refers  to 
the  depth  of  water  under  the  ice,  the  lower  surface  of  the  ice  being 
considered  as  zero,  and  the  distances  being  measured  in  feet  and 
tenths.  Where  not  otherwise  stated,  the  ice  was  smooth  on  the  lower 
side.  Some  curves  were  made  with  ice  broken  and  tilted,  but  the 
results  were  (juite  different  from  those  obtained  with  smooth  ice,  and  the 
results  ha\  e*been  given  in  separate  tallies  (XXIX  to  XXXIII).  The 
retarding  influence  of  the  rough  ice  was  decidedly  greater  than  that  of 
the  smooth  ice  and  is  so  variable  that  no  law  can  be  formulated. 

Tables  XIX,  XXI,  XXIII,  XXV,  and  XXVII  are  derived  from  the 
preceding  tables  by  platting  the  vertical  velocity  curves,  as  shown  by 
the  original  data,  and  taking  from  this  curve  the  velocities  at  regu- 
lar intervals,  one-tenth  of  the  depth  apart.  The  sum  of  these  veloci- 
ties divided  by  10  will  give  the  mean  in  the  section. 

In  Table  XIX,  and  the  others  of  a  similar  character,  a  column 
has  been  added,  headed  "Per  cent  of  mean."  The  figures  of  this 
column  arc  obtained  by  dividing  the  corresponding  figures  in  the  adja- 
cent column  by  the  mean  velocity,  which  reduces  the  data  for  each 
velocity  curve  to  a  similar  curve  whose  mean  is  KM),  and  asthedepths 
are  then  expressed  as  percentages  of  total  depth,  and  the  velocities 
as  percentages  of  the  mean  velocity,  the  comparison  between  the 
curves  is  facilitated.  In  all  cases  for  which  the  data  are  included 
within  these  tabh-s  the  ice  on  the  surface  was  smooth  both  on  its 
upper  and  lower  faces.  The  few  velocity  curves  taken  at  times  when 
the  ice  was  broken  and  tilted  are  shown  in  separate  tables. 
ikk  70 — u:j  4 


50 


FLOW  OF 


RIVERS  NEAR  NEW  YORK  CITY. 


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PKESSEY.] 


FLOW  OF  RIVERS  UNDER  ICE. 


51 


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PRESSEY.] 


FLOW  OF  RIVERS  UNDER  ICE. 


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FLOW   OF  RIVERS  NEAR  NEW  YORK  CITY. 


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58  FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY.  [no. 76. 


Table  XXIV. — Velocities  in  vertical  sections  under  ice  on  Catskill  Creek.® 


Date  

Feb 

.  27. 

Feb 

.  27. 

Feb 

27. 

Feb.  27. 

Feb 

.  27. 

Station  

23. 

23. 

30. 

40. 

a 

). 

Gage  height  

4. 

V). 

4. 

4. 

50 

4. 

70. 

Total  depth  

4. 

1. 

4. 

4. 

5. 

5. 

8. 

4. 

7. 

Thickness  of  ice. . . 

] 

1. 

2. 

1. 

5. 

Depth  of  water  

3. 

4. 

4. 

2. 

3. 

5. 

4. 

6. 

3. 

2. 

Depth. 

v  e- 
locity. 

Depth. 

v  e- 

Depth. 

Ve- 
locity. 

Depth. 

Ve- 
locity. 

Depth. 

Ve- 
locity. 

Ft. per 

Ft.  per 

Ft.  per 

Ft.  per 

Ft 

Feet. 

sec. 

Feet. 

sec. 

Feet. 

sec. 

Feet. 

sec. 

Feet. 

sec^ 

0.4 

1.37 

0.3 

1.50 

0.3 

1.42 

0.3 

2. 31 

0.3 

1. 55 

.9 

1.57 

1.94 

.5 

1.84 

2. 41 

1. 77 

1.4 

1.57 

1.2 

1.96 

1.0 

2 

1.1 

2.44 

1. 2 

1.77 

1.9 

1.49 

1.7 

1.89 

1.5 

2.03 

1.0 

2. 47 

1.7 

1.61 

2.4 

1.1(5 

2.2 

1.79 

2.0 

1.91 

2.1 

2. 44 

2.2 

1.135 

2.9 

1.0 

2.7 

1.62 

2.5 

1.74 

2.6 

2.38 

2.7 

1.02 

3.2 

1.37 

3.0 

1.55 

3.1 

2.31 

3.7 

1.07 

3.6 

2.14 

4.1 

1.89 

a  Red  of  stream  rock  ledge  from  0  to  55,  with  gravel  and  silt  over  remainder  of  bed. 


Table  XXV.—  Velocities  at  regular  intervals  in  vertical  sections  on  Catskill  Creek 
under  ice.  deduced  from  data  in  Table  XXIV. 

[Velocities  in  feet  per  second.] 


Feb.  27. 


Depth  in  feet. 


Veloc- 
ity. 


0.05   I  1.24 

.15...  i  1.42 

.25  j  1755 

.35...  .J  1.60 

.45  |  1.56 

.55  !  1.48 

.65  !  1.34 

.75    1.19 

.85   1.01 

.95...   .81 

Mean   1.32 


Per 
cent  of 
mean. 


94 
108 
117 
121 
IIS 
112 
102 
90 
77 
61 

LOO 


Feb.  27. 


Veloc- 
ity. 


1 .  45 
1.82 
1 . 95 
1.91 
1.86 
1.75 
1.60 
1.42 
1.19 
.85 

1.58 


Per 
cent  of 
mean. 


92 
115 
123 
121 
118 
111 
101 
90 
75 
54 


LOO 


Feb.  27.  Feb.  27. 


Veloc- 
ity. 


1.21 
1.85 
1.98 
2.04 
2.03 
1.95 
1.85 
1.72 
1.55 
1 . 32 

1 .  75 


Per 
cent  of 
mean. 


106 
113 
117 
116 
111 

UK) 

;ts 


100 


Veloc- 
ity. 


2.30 
2.42 
2.46 
2.47 
2. 44 
2.40 
2. 32 
2.20 
2.04 
1.75 


Per 
cent  of 
mean. 


101 
106 
108 
108 
107 
105 


KM) 


Feb.  27. 


Veloc- 
ity. 


Per 
cent  of 
mean. 


1.38 
1.68 
1.76 
1.78 
1.71 
1.58 
1.43 
1.22 
1.01 
.75 

1.43 


97 
117 
122 
124 
120 
111 
100 
85 
70 
54 


100 


The  data  contained  in  Tables  XIX  and  XX  have  been  rearranged 
and  combined  in  Table  XXVI.  The, mean  of  the  26  vertical  velocity 
curves  taken  on  the  Wallkill  is  shown  in  the  ('011111111  headed  u  Mean." 
The  26  curves  arc  then  separated  according  to  the  depth  of  water 
under  ice  at  the  point  whence  the  observations  were  taken.  In  two 
observations  the  depth  of  water  was  less  than  5  feet;  in  thirteen  it 
was  from  5  to  10  feet,  and  in  1 1  it  was  from  10  to  20  feet. 


PKESSEY.] 


FLOW  OF  RIVERS  UNDER  ICE. 


To  bring  out  graphically  the  form  of  the  vertical  velocity  curve 
under  ice  the  data  in  Table  XXVI  have  been  plotted  in  where 
the  solid  line  represents  the  mean  of  the  2G  vertical  velocity  curves 
taken  in  the  Wallkill.  It  will  be  noted  thai  a  decided  drag  occurs 
at  the  surface  as  well  as  at  the  bottom  of  this  mean  curve;  that 
the  maximum  velocity  occurs  at  a  point  about  0. 35  of  the  depth, 
and  that  the  mean  velocity  in  the  vertical  occurs  at  about  0.13  and 
0.73  of  the  depth.  There  will,  in  general,  always  be  two  points  of 
mean  velocity  in  vertical  velocity  curves  taken  under  ice. 

The  results  shown  in  the  three  last  columns  in  Table  XXV 1  are  also 
plotted  in  fig.  5,  and  show  the  effect  of  the  variation  in  depth  upon 
the  form  of  the  curve.  It  will  be  seen  that  the  curves  drag  more  at 
shallow  depths,  the  curve  for  depths  under  5  feet  being  more  concave 
than  the  others,  the  curve  representing  the  measurements  when  the 
water  was  from  -r>  to  10  feet  in  depth  being  next  most  concave,  while 
the  curve  representing  the  deepest  measurement  is  flattest.  This 
seems  reasonable,  and  would  probably  hold  true  in  all  rivers. 

It  is  frequently  desirable  to  measure  the  flow  of  the  river  when 
frozen  over.  This  can  best  be  done  by  taking  a  large  number  of 
point  measurements,  as  represented  in  fig.  4.  but  this  is  a  slow  process, 
so  that  it  is  important  to  know  at  what  point  the  measurement  of 
velocity  can  be  made  which  will  represent  the  mean  velocity  in  the 
vertical  section. 

It  will  be  seen  from  the  four  curves  in  fig.  -r>  that  measurements  made 
at  0.13  and  0.73  of  the  total  depth  measured  from  the  bottom  of  the  ice 
will  represent  in  general  the  mean  velocity  in  a  vertical  on  a  stream 
with  the  same  general  character  as  the  Wallkill.  The  variation,  how- 
ever, between  the  curves  representing  different  depths  is  greater  at 
these  two  points  than  at  points  six  hundredths  and  two-thirds  of  the 
depth.  At  these  two  points  the  curves  almost  coincide.  The  varia- 
tion between  the  various  curves  was  less — in  fact  within  limits  only 
one-half  as  great — at  two-thirds  depth  as  at  six-hundredths  depth. 
This  shows  that  in  these  curves  the  limit  of  error  is  least  when 
measurements  are  made  at  two-thirds  depth  and  a  coefficient  is  applied 
to  determine  the  mean  velocity.  The  mean  curve  shows  a  velocity  of 
ln5  per  cent  of  the  mean  at  two-thirds  depth,  so  that  it  would  appear 
that  the  most  accurate  method  of  determining  the  velocity  under 
ice  by  observation  at  one  point  in  the  vertical  would  be  to  hold  the 
meter  at  two-thirds  depth  and  apply  a  coefficient  of  0.95  to  the 
observed  velocity  at  that  point.  This  would  give  a  better  result  than 
measuring  directly  the  velocity  at  0.13  or  0.73  of  the  depth.  In 
Table  XXVII  is  shown  the  means  of  all  the  curves  in  the  Ksopus, 
Rondout,  and  Wallkill.  These  have  been  plotted  in  tig.  6.  The 
variation  of  these  three  curves  is  not  large,  showing  that  the  curve  as 


60 


FLOW   <>1    RIVERS  NEAR  NEW  YORK  CITY. 


[no.  76. 


plotted  represents  fairly  well  the  typical  velocity  curve  of  rivers  of 
this  character  under  ice  cover.  In  Table  XXVIII  the  results  shown 
in  all  the  preceding  tables,  for  ice  cover,  including-  Wallkill,  Esopus, 
Rondout,  and  Catskill,  have  been  combined  according  to  depth  of 


Depths  in 
decimal 
parts  of 
total. 

.10 


.20 


.30 


.40 


.50 


I.IK) 


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50 


60 


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120 


70  80  90  100 

Velocity  in  terms  of  mean  velocity  =  100. 

Fk;.5.— Mean  vertical  velocity  curves  on  Wallkill  River,  with  ice  cover,  showing  th<>  effect 
upon  the  curve  of  variation  in  depth  of  water. 

Note. — The  solid  line  is  the  mean  of  2it  vertical  velocity  curves  at  all  depths;  the  dot-dash  lino 
the  mean  of  two  vertical  velocity  curves  at  depths  less  than  5  feet;  the  dotted  line  the  mean  of 
13  vertical  velocity  curves  at  depths  between  5  and  10  feet,  and  the  dash-two-dot  lines  tin-  mean 
of  11  vortical  velocity  curves  at  depths  greater  than  10  feet. 

water  under  the  ice,  and  have  been  plotted  in  fig.  7,  together  with  the 
mean  of  all  47  curves.  The  form  of  these  curves  does  not  differ 
materially  from  those  for  the  Wallkill,  plotted  in  fig.  5.  The  point 
at  which  these  curves  fall  closest  together  is,  however,  somewhat 
higher,  ;ii  0.6  depth.    To  a  single  measurement  made  at  0.6  depth  a 


PKESSEY.] 


FLOW  OF  RlVEBS   I'NDEK  IOF. 


61 


coefficient  of  0.!>2  should  be  applied  1<>  obtain  the  mean  velocity  in  1  he 
vertical  section,  while  the  coefficient  0.95  should  be  applied  to  a  single 
measurement  made  at  two-thirds  depth,  as  in  the  ease  of  the  Wall- 
kill,  shown  in  fig.  5. 


Depths  in 
decimal 


1.00  |  |  |  

50  60  70  80  00  100  110  120  130 

Velocity  in  terms  of  mean  velocity  =  100 

FlG.  6.— Mean  vertical  velocity  curves  on  Esopns  and  Rondout  creeks  and  Wallkill  River, 
under  ice  cover,  showing  the  comparatively  slight  variation  in  vertical  velocity  curves  of  rivers 
of  this  character. 

Note.— The  solid  line  shows  the  inean  vertical  velocity  curve  on  the  Wallkill  and  Rondout 
with  the  ice  broken  and  tilted,  and  shows  the  decided  drag  caused  by  the  increased  friction  at 
the  surface. 

There  are  many  engineers  who  prefer  to  measure  the  velocity  at 
mid-depth,  and  apply  a  coefficient  to  obtain  the  mean  velocity  in  the 
vertical  section.  The  observations  recorded  in  Table  XXVII  show 
that  the  proper  coefficient  to  apply  is  0.88.  Observat  ions  upon  the 
How  of  water  under  ice  cover  on  the  Upper  Mississippi  were  made  by 


62 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY. 


[no.  76. 


A.  ().  Powell,  assistant  engineer,  under  the  direction  of  Col.  Chas.  J. 
Allen,  Corps  of  Engineers,  U.  S.  Army,  in  1882  and  1890,  and  the  pub- 


 ^ 

\X 

»  \\ 

\ 

-A  

\ 

\ 

\  X 

V  v 

Mean,  genera/  curi/e 

 Mean  of  curves,  c/epfn  /ess  // 

 Mean  of  curves,  depth  be/ ween  J. 

?an  5' 
iand/0' 
land 20' 

V   i  ! 

/vi  ca// 

5,  UC/JJ//  u 

\  V 

i  // 

i 

— # 

/ 

/// 

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''ft 

— ^ 

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/  / 

y,/ / 

// 

J 



/  -> 

y  / 
/ 

70  80  90  100 

Velocity  in  terms  of  mean  =  100. 

>f  water  under  i 


110 


120 


130 


cover  with  the  mean  of 


FlG.  7. — Comparison  of  curves  for  various  depths 
all  curves  taken  under  ice. 

Note. — The  solid  line  is  the  mean  curve  and  represents  17  vertical  velocity  curves.  The  dash- 
dot  line  is  the  mean  of  7  curves  with  depths  of  water  under  ice  of  less  than  5  feet.  The  dotted  line 
is  the  mean  of  29  vertical  velocity  curves  with  depths  of  water  under  ice  ranging  from  5  to  10 
feet,  and  the  dash-two-dot  line  is  the  mean  of  11  vertical  velocity  curves  for  a  depth  of  water 
under  ice  ranging  from  10  to  20  feet. 


Lished  results0  show  that  this  coefficient  varied  from  0.87380  to 
0.88057.* 


«  Ann.  Rept.  Chief  of  Engineers,  U.  S.  Army,  Part  III,  1890. 

''Owing  to  the  inaccuracies  in  observations  of  this  kind,  it  does  not  seem  to  the  author  justi- 
fiable to  carry  the  coefficient  beyond  the  second  place  of  decimals.  The  results  obtained  in 
the  streams  in  New  York  agree  with  those  in  the  Mississippi  to  the  second  place  of  decimals. 


PRESSEY.] 


FLOW  OF  KIVFRS  UNDFR  ICE. 


63 


Table  XXVI.—  Mean  vertical  velocity  curve  on  Wa  Ilk  ill  River  and  curves  sepa- 
rated according  to  depths  of  water. 


[Velocities  given  in  percentages  of  mean  velocity.] 


26. 

13. 

11. 

Depth  of  water  under  ice. 

Depth  below  bottom  of  ice. 

Mean. 

I  .ess  than 

Between  5  Between  10 

5  feet. 

and  10  feet. 

and  20  feet. 

0.05  

84.0 

81.5 

83.2 

85.5 

.15  .     

103.0 

107.5 

103.7 

101.5 

.25    

112.0 

117.0 

114.0 

108.6 

-35      

1 14.  S 

11!).  0 

116.8 

111.5 

.45   

L14.0 

117.0 

*  115.7 

111.4 

.55.    

lit),  s 

11:5.5 

111.8 

109.3 

<M      

105.8 

107. 5 

105.5 

105.9 

.75    _   

118.4 

96.0 

!»;.  6 

100.9 

.  85  —      

87.5 

81.0 

84.5 

92. 1 

.95       

09.7 

60.0 

68.2 

73.3 

Mean  

100  0 

100.0 

llKI.lt 

100.0 

Table  XXVII. — Mean  vertical  velocity  curves  for  Esopus,  Rondout .  and  Wallkill, 

based  upon  a  mean  of  100. 


Stream    

Number  of  velocity  curves   

Depth  below  bottom  of  ice 

0.05  

.15     

.25   i   

.35.   1   

.45   

.55   

.65    

.75  

So    

.95     

Mean   


Esopus. 

Rondout. 

Wallkill. 

8. 

8. 

26. 

Mean. 

Mean. 

Mean. 

88.2 

&5.9 

84.0 

104.7 

103.1 

103.0 

112.9 

112.1 

112.0 

115.9 

115. 5 

114.8 

114.6 

115.2 

114.0 

111.8 

111.7 

110.8 

106.8 

105.4 

105. 8 

97.4 

96.8 

98.4 

84.6 

85.4 

87.5 

63. 1 

68.9 

69.7 

100.0 

100.0 

100.0 

64 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY. 


[NO.  70. 


Table  XXVIII. — Mean  velocity  curves  upon  Wallkill^Esopus^Ron^ut^and  Cats- 
kill  for  various  depths. 

[Velocities  given  in  percentages  of  mean  velocity.] 


Number  of  velocity  curves. 

29.  11. 

47. 

Depth  below  bottom  of  ice. 

Depth  of  water  under  ice. 

Mean  of  all 
curves. 

Less  than 
5  feet. 

5  to  10 
feet. 

10  to  20 
feet. 

88.0 
109.6 
116.7 
118.4 
116. 1 
111.0 

103. 7 
93. 2 
80. 3 
63.0 

1 

85  St  •            OR  S 

85.8 
104.1 
112.6 
115.5 
114.5 
111.1 
105.5 
97.3 
85.8 
67.8 

103. 8 
113. 2 
116.2 
115.3 
111.8 
105. 8 
96. 9 
84.8 
66.9 

101.5 
108.6 
111.5 
111.4 
109: 3 
105. 9 
100.9 
92.1 
73. 3 

.65         

.85     

.95  

100.0 

100.0 

100.0 

100.0 

FLOW  OF  RIVERS  UNDER  ICE,  BROKEN  AND  TILTED 

COYER. 

A  few  vertical  velocity  curves  were  taken  on  the  Wallkill  and  Ron- 
dout  when  the  ice  on  the  river  was  broken  and  more  or  less  tilted. 
No  general  law  can  be  determined  for  such  conditions,  as  the  imped- 
ing power  of  the  ice  varies  between  wide  limits.  It  is  interesting, 
however,  to  note  in  a  general  way  the  effect  of  the  ice.  The  drag  al 
the  surface  is  greatly  increased  and  the  curve  is  changed  considerably 
in  form.  In  Tables  XXIX  to  XXXII  will  be  found  the  results  of  the 
measurements,  while  in  Table  XXXIII  is  the  summary  of  these 
results.  The  mean  curve,  as  shown  in  Table  XXXIII,  is  plotted  in 
fig.  8,  together  with  the  mean  curves  when  the  ice  covering  was 
smooth.  It  will  be  seen  from  this  diagram  that  the  point  of  maximum 
velocity  is  0.55  of  the  depth,  much  lower  than  with  smooth  ice;  that 
the  surface  velocity  is  much  less,  and  that  the  bottom  velocity  is 
greater.  This  curve  would  without  doubt  vary  greatly  at  different 
times,  depending  upon  the  condition  of  the  tee,  so  that  measurement 
at  any  point  for  the  determination  of  the  mean  velocity  would  not 
be  advisable.  Point  measurements  at  frequent  intervals  would  be 
necessary  in  order  to  obtain  reliable  results.  It  is  not  considered 
that  the  results  show  any  decided  law  of  relation  between  velocities 
at  various  depths,  but  the  general  form  of  the  curve  is  characteristic 
in  conditions  similar  to  those  under  which  these  were  taken. 


pressky]  FLOW  OF  RIVERS   UNDER  ICE.  65 


Table  XXIX. — Velocities  in  vertical  section  on  WaUhill  River  under  ice  broken 

and  tilted. 


Date  

Point  of  measure- 
ment  

(■iiigo  height  

Total  depth  

Thickness  of  ice. . . 
Depth  of  water... 

Dec.  19. 

115. 
13.70. 
18.0. 
4.0. 
14. 0. 

Dec.  19. 

95. 
13. 70. 
16.01. 
0.0i. 

16.0. 

Dec.  ID. 

85. 
13.70. 
15.64. 

0.01. 

15. 6. 

Dec.  ]L9. 

75. 
13.70. 
14.5. 
1.0. 
13. 5. 

Jan.  23. 

30. 
17. 83. 
14.4. 
1.4. 
13.0. 

Depth. 

Veloc- 
ity. 

Depth. 

Veloc- 
ity 

Depth. 

Veloc- 
ity. 

Depth. 

Veloc- 
ity. 

Depth. 

Veloc- 
ity. 

Ft.  pet- 

Ft.  per 

Ft.  per 

Feet. 

Ft.  per 

Ft.  per 

Feet. 

sec. 

Feet. 

sec. 

Feet. 

sec. 

sec. 

Feet. 

sec. 

0.5 

0.30 

1.5 

2.73 

i.i 

2.52 

1.0 

1.52 

1.0 

1.72 

1.5 

1.27 

3.5 

3.30 

3.1 

3.08 

3.0 

2.50 

2.5 

1.96 

3.5 

2.  as 

5.5 

3. 48 

5.1 

3.48 

5.0 

2.94 

4.5 

2.26 

5.5 

2.  71 

7.5 

3.84 

7.1 

3.91 

7.0 

3.03 

6.5 

2.56 

7.5 

2. 99 

9.5 

4. 12 

9.1 

3.95 

9.0 

3. 13 

8.5 

2.64 

9.5 

2.94 

11.5 

3.93 

11.1 

3.86 

11.0 

2.88 

10.5 

2.24 

11.5 

2.64 

13.5 

3.60 

13.1 

3.50 

13.0 

2.45 

12.5 

1.67 

13.5 

1.94 

15.5 

2.61 

15.1 

2.64 

Table  XXX. — Velocities  at  regular  intervals  in  vertical  section  on  Wallkill  River 
undo-  ice  broken  and  tilted,  deduced  from  Table  XXIX. 


Depth  in  parts 
of  total. 


9 


Dec.  19. 


Dec.  19. 


Veloc- 
ity in 
feet 
per 
second. 


Mean 


1.10 
1.94 
2.41 
2.70 
2.90 
3.00 
2.94 
2.80 
2.55 
2.05 

2.44 


Pei- 
cent  of 


45 


111 
119 
123 
120 
115 
104 
84 


Veloc- 
ity in 
feet 
per 

second, 


100 


2.35 
3.00 
3.35 
3.65 
3.90 
4.10 
4.07 
3.88 
3.60 
2.85 


3.48 


Dec.  19. 


Per 
cent  of 
mean. 


Veloc- 
ity in  |  Per 
feet  !  cent  of 
per  mean, 
second 


86 
97 
105 
112 
118 
117 
112 
103 


2.40 
2.95 
3.33 
3.62 
3.86 
3.95 
3.90 
3.  76 
3.42 
2.80 


100       3. 40 


71 
87 
98 
106 
113 
116 
115 
111 
101 


100 


Dec.  19. 


Jan.  23. 


Veloc- 
ity in 
feet 
per 

second. 


1.40 
1.94 
2.60 
2. 87 
3.04 
3.11 
3.08 
2.98 
2. 78 
2.50 


Per 
cent of 
mean. 


Veloc- 1 

ity  in  |  Per 
feet  ! cent  of 
per  mean, 
second. 


54 
74 
99 
109 
115 
118 
117 
L13 
106 
S5 


2. 63 


L00 


irk  76 — 03  i 


66 


FLOW  OF  RIVERS  NEAR  NEW   YORK  CITY. 


[no.  76. 


Table  XXXl.'—M'locitic.s  in  vertical  sections  on  Rondout  Creek  at  Rosendale 
under  ice  broken  and  tilted. 


Date   

Dec.  6. 

Jan.  14. 

Jan.  14. 

Jan.  14. 

Point  of  measurement. 

50. 

4 

0. 

50. 

60. 

Gage  height  

6. 

80. 

7. 

00. 

7 

00. 

7. 

00. 

5 

6. 

4. 

8. 

6 

.4. 

6 

4. 

Thickness  of  ice  

0 

2. 

0 

8. 

0 

.4. 

0 

4. 

5 

4. 

4 

0. 

6 

.0. 

6 

0. 

Veloc- 

Veloc- 

Veloc- 

Veloc- 

Depth. 

ity  in 
feet  per 

Depth. 

ity  in 
feet  per 

Depth. 

ity  in 
feet  per 

Depth. 

ity  in 
feet  per 

second. 

second. 

second. 

second. 

0.3 

0. 21 

0.5 

0.35 

0.5 

0. 72 

0.5 

0.55 

1.3 

.54 

1.5 

.75 

1.5 

.82 

1.5 

.87 

2.8 

.55 

2.5 

.97 

2.5 

.90 

2.5 

1.17 

3.8 

.57 

3.5 

.85 

3.5 

.90 

3.5 

1.15 

4.9 

.36 

4.5 

.87 

4.5 

1.10 
.86 

5.5 

.72 

5.5 

Table  XXXII. — Velocities  at  regular  intervals  in  vertical  section  on  Rondout 
Creek  under  ice  broken  and  tilted,  deduced  from  Table  XXXI. 


Veloc- 
ity in 
feet  per 
second. 

Per  cent 
of  mean. 

Veloc- 
ity in 
feet  per 
second. 

Per  cent 
of  mean. 

Veloc- 
ity in 
feet  per 
second. 

Per  cent 
of  mean. 

Veloc- 
ity in 
feet  per 
second. 

Per  cent 
of  mean. 

0.25 

53 

0.24 

3* 

0. 67 

81 

0.48 

51 

.46 

99 

.40 

57 

.76 

92 

.68 

72 

.54 

115 

.55 

79 

.82 

100 

.87 

93 

.57 

122 

.70 

100 

.88 

107 

1.06 

112 

.57 

122 

.85 

121 

.90 

110 

1.19 

127 

.56 

120 

.95 

136 

.91 

111 

LIS 

126 

.  55 

117 

.97 

139 

.90 

109 

1.14 

121 

.50 

107 

.95 

ia5 

.88 

107 

1.06 

113 

.43 

92 

.88 

126 

.82 

100 

.96 

102 

53 

.51 

73 

.69 

83 

78 

83 

.468 

100 

.70 

100 

.823 

100 

.941 

100 

prbssey.]  QUALITY  OF  WATER.  67 


Table  XXXIII. — Summary  of  curves  on  Wollkill  and  Rtnidont,  under  ice  broken 

and  tilted. 


Wallkill. 

Rondout. 

5. 

4. 

9. 

Depth  of  water  below  bottom  of  ice. 

13  to  16  ft. 
River  bed: 
Silt. 

4  to  6  ft. 
River  bed: 

Bowlders 
and  gravel. 



Mean. 

63.  0 

54. 8 

59. 3 

82.  6 

HU.  U 

iir.4 

96.8 

97. 1 

.35       —  

106.8 

110.2 

108.3 

.45       

114.0 

120.0 

116.7 

.55..     

118.8 

123.2 

120.8 

.65    

117.6 

121.5 

119.3 

.75.        

112.4 

115.5 

113.8 

.85,..         

102. 4 

105.0 

103.6 

.95      

85.0 

73.0 

79.7 

Mean   

100.0 

100.0 

100.0 

QUALITY  OF  KIVER  WATER. 

A  study  of  the  turbidity,  color,  alkalinity,  and  hardness  of  these 
streams  lias  been  made  in  conjunction  with  the  discharge  measure- 
ments. It  is  thought  that  t lie  information  derived  from  such  deter- 
minations will  be  of  value  to  engineers  invest  igat  ing  the  future  supply 
of  New  York  City. 

TURBIDITY  AND  COLOR. 

Water  ii# it s  ideal  condition  is  perfectly  clear  and  limpid,  and  has 
a  slightly  blue  color.  Filtered  water,  distilled  water,  and  many 
spring  waters  approach  closely  to  the  ideal  water.  Most  river  waters 
are,  however,  either  colored  by  contact  with  peat,  muck,  or  decaying 
vegetation,  or  are  turbid  by  reason  of  mud  or  silt  carried  in  suspen- 
sion. Muddy  waters  are  often  spoken  of  as  colored  waters,  and  in  a 
sense  this  is  correct  where  the  mud  consists  of  clays  or  other  mate- 
rials having  distind  colors,  but  for  convenience  of  classification  it  is 
better  to  refer  to  such  waters  as  turbid  waters,  and  to  limit  the  term 
"colored  waters"  to  those  containing  in  solution  vegetable  matters 
which  color  them. 

It  has  been  observed  that  highly  colored  waters  are  usually  free 
from  turbidity,  and  vice  versa,  this  being  due  to  the  fact  that  colored 
waters  usually  flow  from  drainage  areas  underlain  by  hard  rocks  not 
easily  disintegrated,  or  from  regions  where  the  soils  are  firm  or  sand)', 
and  especially  from  swamps.  On  such  areas  there  is  but  little  mate- 
rial that  would  be  washed  from  the  river  banks  and  held  in  suspen- 
sion, while  the  coloring  material  is  present  in  the  greatest  abundance. 
In  many  parts  of  the  United  States  shales  or  other  soft  materials 


68 


FLOW   OF  RIYFKS  NEAR  NEW  YORK  CITY. 


[NO.  76. 


form  the  underlying  beds.  These  readily  disintegrate  and  form  clay 
soils  that  are  readily^  ashed  by  hard  rains.  Waters  from  such  areas 
arc  usually  turbid  and  very  highly  colored. 

Turbidity  and  color  are  principally  important  in  their  effect  upon 
the  appearance  of  water,  whereas  the  other  impurities  discussed  in 
this  paper  have  absolutely  no  effect  upon  the  appearance,  and  can  be 
found  only  by  their  chemical  action. 

TURBIDITY. 

The  turbidity  of  water  is  a  subject  of  great  importance  to  the  sani- 
tary engineer.  In  questions  of  water  supply,  turbidity  is  often  the 
important  feature  in  the  selection  of  a  source  of  town  supply;  the 
number  of  days  upon  which  the  turbidity  is  above  a  certain  fixed 
standard  is  also  important,  in  that  it  may  determine  the  size  of  reser- 
voir required  to  store  clear  water  sufficient  to  tide  over  the  time  of 
greatest  turbidity,  or  for  the  sedimentation  of  suspended  matters  in 
the  reservoir  water.  The  importance  of  this  subject  varies  with  the 
part  of  the  country  studied,  the  waters  in  the  New  England  States 
and  Xew  York  being  comparatively  clear,  while  in  the  Southern 
Atlantic  States  and  in  the  Ohio  and  Mississippi  valleys  high  turbidi- 
ties are  the  rule. 

In  the  Northeast  the  terms  "very  slight,  "slight,"  "distinct,"  and 
"decided"  have  been  used  by  analysts  to  express  the  amount  of  sus- 
pended matter  present.  These  degrees  of  turbidity  have  been  esti- 
mated by  the  appearance  df  the  sample  to  the  eye  when  viewed  toward 
the  light.  As  the  importance  of  these  analyses  has  been  more  appre- 
ciated, particularly  in  connection  with  the  rmrification  of  waters  and 
t  he  extended  studies  upon  waters  of  high  turbidity,  it  has  been  found 
that  a  more  definite  scale  was  necessary  in  order  that  proper  compari- 
sons of  waters  from  various  sources  might  be  made. 

In  the  filtration  of  water  the  engineer  desires  to  know  the  amount 
of  coagulant  necessary  to  properly  clarify  the  water,  and  it  has  been 
found  that  the  turbidity  gives  a  reliable  index  of  the  quantity  of 
coagulant  required.  The  object  of  the  more  recent  studies  has  been, 
therefore,  to  express  it  numerically  on  some  scale,  referred  to  some 
standard,  which  can  be  easily  reproduced  and  will  be  permanent. 

There  has  been  considerable  difference  of  opinion  as  to  the  proper 
standard  for  turbidity  comparisons,  and  some  confusion  has  resulted. 
It  is  important  that  any  standard  selected  should  be  applicable  to 
both  field  and  laboratory  practice,  and  that  observations  made  by 
different  met  hods  should  be  readily  comparable. 

The  United  States  Geological  Survey  has  had  occasion,  from  time 
to  time,  to  make  observat  ions  of  t  urbidity  of  riversof  which  discharge 
measurements  were  made.  Realizing  the  importance  of  a  uniform 
standard  for  turbidity,  the  Survey  has  cooperated  with  Mr.  Allen 


PRESSEY.] 


TURBIDITY. 


69 


Hazen  and  Mr.  George  C.  Whipple  in  order  that  such  a  standard 
might  be  adopted.  Mr.  Hazen  and  Mr.  Whipple  have  made  joint 
investigations  and  studies,  and  have  recommended  the  standard  given 
below.  This  will  be  used  in  the  future  by  the  Survey,  and  it  is  hoped 
may  be  adopted  generally  throughout  the  United  states. 

PROPOSED  TURBIDITY  STANDARD. a 

The  standard  of  turbidity  shall  be  a  water  which  contains  100  parts 
of  silica  per  million  in  such  a  state  of  fineness  that  a  bright  platinum 
wire  1  millimeter  in  diameter  can  just  be  seen  when  the  center  of  the 
wire  is  100  millimeters  below  the  surface  of  the  water  and  the  eye  of 
the  observer  is  1.2  meters  above  the  wire,  the  observation  being  made 
in  the  middle  of  the  day,  in  the  open  air,  but  not  in  sunlight,  and  in 
a  vessel  so  large  that  the  sides  do  not  shut  out  the  light  so  as  to  influ- 
ence the  results.    The  turbidity  of  such  water  shall  be  100. 

The  turbidity  of  waters  more  turbid  than  the  standard  shall  be  com- 
puted as  follows:  The  ratio  of  the  turbidity  of  the  water  to  100  shall 
be  as  the  extended  volume  is  to  the  original  volume,  when  the  water 
is  diluted  with  a  clear  water  until  the  mixture  is  of  standard  turbidity. 

The  turbidities  of  waters  lower  than  the  standard  should  be  com- 
puted as  follows:  The  ratio  of  the  turbidity  of  the  water  to  100  shall 
be  as  the  ratio  of  the  original  volume  of  water  of  standard  turbidity  is 
to  the  extended  volume  when  such  water  is  diluted  with  a  clear  w  ater 
until  its  turbidity  is  equal  to  that  of  the  water  under  examination. 

This  standard  can  be  used  in  both  field  and  laboratory.  In  the  field 
the  wire  method  will  be  carried  out  as  at  present,  except  for  a  new 
graduation,  while  in  the  laboratory  the  methods  of  dilution  and  com- 
parison now  in  use  for  the  silicia  standard  will  be  used. 

METHOD  OF  APPLICATION  TO  THE  PLATINUM-WIRE  PROCESS. 

A  rod  with  a  platinum  wire  inserted  in  it  at  a  fixed  point  and 
projecting  from  it  at  a  right  angle  will  be  used  as  at  present.  The 
graduation  shall  be  as  follows:  The  graduation  mark  of  100  shall  be 
placed  on  the  head  at  a  distance  of  100  millimeters  from  the  center  of 
the  wire.  Other  graduations  will  be  made,  based  on  the  best  obtain- 
able data,  in  such  a  way  that  when  a  water  is  diluted  the  leadings 
will  decrease  in  the  same  proportion  as  the  percentage  <  f  the  original 
water  in  the  mixture.  Such  a  rod,  having  the  graduation  shown  in 
the  table  below,  shall  be  known  as  the  Ignited  States  (Geological  Sur- 
vey turbidity  rod  of  1902.  When  this  rod  is  immersed  in  water  the 
visibility  of  the  projecting  platinum  wire  at  the  depth  from  the  sur- 
face shown  in  the  second  column  will  determine  the  degree  of  tur- 
bidity, as  indicated  in  the  first  column. 


"  From  a  letter  signed  by  Messrs.  Allen  Hazen  and  George  C.  Whipple 


70  FLOW  OF  RIVEBS  NEAR  NEW  YORK  CITY.  [no. 76. 


Graduation  of  rod. 


Turbidity. 

Depth  of 
wire. 

Correspond- 
ing value  on 
reciprocal 
scale. 

Turbidity. 

Depth  of 
wire. 

Correspond- 
ing value  on 
reciprocal 
scale. 

Mm. 

Mm. 

1095 

0.  023 

70 

138.  0 

0.  184 

8 

971 

.026 

75 

130.0 

.196 

9 

873 

.029 

80 

122. 0 

.208 

10 

794 

.  032 

85 

116.0 

.219 

11 

729 

.035 

90 

110.0 

.230 

12 

674 

.038 

95 

105.  0 

.242 

13 

627 

.041 

100 

100.0 

.254 

14 

587 

.043 

110 

93.0 

.273 

15 

551 

.046 

120 

86.0 

.295 

16 

520 

.049 

130 

81.0 

.314 

17 

493 

.052 

140 

76.0 

.334 

18 

468 

.054 

150 

72.0 

.35 

19 

446 

.057 

160 

68.7 

.37 

20 

426 

.060 

180 

62.4 

.41 

22 

391 

.065 

200 

57.4 

.44 

24 

361 

.070 

250 

49.1 

.52 

26 

336 

.076 

300 

43.2 

.59 

28 

314 

.081 

350 

38.8 

.65 

30 

296 

.086 

400 

35.4 

.72 

35 

257 

.099 

500 

30.9 

.82 

40 

228 

.111 

600 

27.7 

.92 

45 

205 

.  124 

800 

23. 4 

1. 09 

50 

187 

.136 

1000 

20.9 

1.21 

55 

171 

.148 

1500 

17.1 

1.49 

60 

158 

.160 

2000 

14.8 

1.72 

65 

147 

.172 

3000 

12.1 

2.10 

This  table  is  compiled  from  observations  made  at  Cincinnati,  St. 
Louis,  New  Orleans,  Pittsburg,  Brooklyn,  Philadelphia,  and  Boston, 
for  records  of  which  we  are  indebted  to  several  observers.  The  values 
of  the  turbidities  by  the  reciprocal  scale  are  included  in  the  table  as 
a  matter  of  convenience,  but  they  do  not  form  a  part  of  the  standard. 

This  graduation  is  subject  to  revision  whenever  additional  daia 
shall  make  it  necessary,  and  revised  rods  shall  be  designated  by  the 
same  name,  but  with  the  year  of  revision  substituted  for  1902.  The 
revisions  shall  have  as  their  basis  the  one  hundred  mark,  100  milli- 
meters  from  the  wire. 

Near  the  end  of  the  rod,  at  a  distance  of  1.2  meters  from  the  plati- 
num wire,  a  wire  ring  shall  be  placed  directly  above  the  wire,  through 


PKKSSKV. 


TURBIDITY. 


71 


which  the  observer  will  look,  tlie  object  of  the  ring  being  to  control 
the  distance  from  the  wire  to  the  eye. 

When  the  turbidity  is  greater  than  500  the  water  should  be  diluted 
before  the  observation  is  made.  When  the  turbidity  is  below  7  this 
method  can  not  be  used,  and  comparison  should  be  made  with  the 
silica  standard  properly  diluted  in  bottles  or  tubes." 

The  number  obtained  by  dividing  the  weight  of  suspended  matter 
in  parts  per  million  by  the  turbidity  as  obtained  above  shall  be  called 
the  coefficient  of  fineness.  If  greater  than  unity,  it  indicates  that  the 
matter  in  suspension  in  the  water  is  coarser  than  the  standard;  if  less 
than  unity,  that  it  is  finer  than  the  standard. 

This  standard  is  proposed  with  the  idea  of  combining  the  best 
features  of  the  platinum-wire  and  silica  methods  of  measuring  tur- 
bidities as  commonly  used,  and  of  avoiding,  as  far  as  possible,  the 
objections  to  each. 

The  wire  method  is  most  convenient  as  a  field  method.  With  the 
reciprocal  scale,  which  until  now  has  been  used,  it  is  open  to  the  seri- 
ous objection  that  the  readings  are  not  proportional  to  the  amount  of 
turbidity-producing  matter  in  the  water. 

The  silica  standard  is  free  from  this  objection  and  is  more  con- 
venient as  a  laboratory  method,  but  is  not  well  adapted  to  field  use,  and 
is  open  to  the  ^objection  that  it  is  possible  that  the  value  may  be 
changed  by  variations  in  the  fineness  of  the  silica  particles  composing 
the  standard. 

The  standard  now  proposed  is  intended  to  overcome  the  above- 
mentioned  defect  in  the  platinum-wire  method  with  The  reciprocal 
scale,  and  at  the  same  time  to  put  a  control  on  the  value  of  the  silica 
standard.  Applying  it  in  one  way  or  the  other,  it  is  adapted  to  both 
field  and  laboratory  use,  and  the  results  obtained  should  check 
substantially. 

METHOD  OF  MAKING  OBSERVATIONS. 

The  method  of  making  the  observations  by  means  of  the  platinum 
wire  is  as  follows :  Take  a  stick  of  wood  about  5  feet  long  and  five- 
eighths  of  an  inch  square,  more  or  less,  and  insert  a  platinum  wire  at 
a  point  about  1  inch  from  the  end,  so  that  the  wire  will  be  at  right 
angles  to  the  stick  and  project  at  least  1  inch.  The  wire  should  be 
0.04  inch  or  1  millimeter  in  diameter;  the  stick  is  then  graduated,  the 
lines  for  the  various  turbidities  being  at  distances  from  the  wire 
shown  in  the  table  on  page  2. 

Observations  of  turbidity  are  taken  by  putting  this  stick  into  the 
water  under  examination  as  far  as  the  wire  can  be  seen :  the  t  urbidity 
is  then  read  from  the  scale.  This  is  most  conveniently  accomplished 
by  having  a  second  or  smaller  stick  placed  in  front  of  the  first,  the 
end  of  which  is  brought  to  the  water  line  when  the  wire  can  just  be 


^Described  by  Whipple  and  Jaokson  in  Technology  Quarterly,  Vol.  XII,  No.  4,  December,  1899. 


72 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY. 


[no.  76. 


seen.  Upon  removing  1  lie  two  together  the' position  of  the  smaller 
stick  on  the  scale  gives  the  turbidity. 

Observations  are  to  be  taken  in  all  cases  in  open  air,  as  too  high 
results  are  obtained  under  a  roof,  even  with  very  good  light;  and 
they  should  preferably  be  taken  in  the  middle  of  the  day  and  not  in 
direct  sunlight.  In  case  the  sun  is  shining  the  observer  can  stand  so 
that  his  shadow  covers  the  water  immediately  about  the  stick  and 
wire.  The  observations  are  taken  with  the  eye  of  the  observer  at  the 
ring  before  mentioned,  1.2  meters  from  the  wire,  although  some  varia- 
tion in  this  does  not  materially  influence  the  result.  The  wire  should 
be  kept  bright  and  clean.  In  case  it  is  lost,  a  clean  bright  pin  can  be 
used  until  another  wire  can  be  obtained.  When  the  surface  of  the 
water  in  the  stream  is  agitated  by  currents,  waves,  etc.,  or  in  ease  the 
depth  is  not  sufficient  to  give  the  required  immersion,  or  if  for  any 
reason  observations  can  not  be  well  taken  from  the  bank,  a  pail  or 
tub  may  be  filled  with  water  and  the  turbidity  observations  taken  in 
it.  In  many  cases  this  procedure  is  preferable  to  measurement  in  a 
stream,  but  the  observation  must  be  taken  immediately  upon  filling 
the  vessel.  The  diameter  of  the  vessel  should  be  equal  to  at  least 
twice  the  depth  at  which  the  wire  is  immersed,  as  otherwise  the  results 
of  the  reading  will  be  affected. 

When  the  turbidity  of  the  water  is  above  500,  that  is,  in  case  the 
wire  can  be  seen  through  less  than  1  inch  of  water,  the  results  obtained 
by  direct  measurement  are  not  accurate.  Such  water  should  be  diluted 
by  1,2,  or  4  volumes  of  clear  water  in  the  pail  or  tub,  and  thoroughly 
mixed. 

The  turbidity  is  taken  as  above  described,  and  multiplied  by  the 
ratio  that  the  total  volume  of  water  bears  to  the  water  in  the  mixture. 
Clear  water  can  be  obtained  from  a  well  or  any  other  source  obviously 
clear,  or  nearly  so. 

The  statement  of  turbidity  in  such  cases  should  contain  memoranda 
that  the  observations  were  taken  in  this  way,  and  should  give  the 
amount  of  dilution. 

If  waters  have  a  turbidity  less  than  7  direct  leading  can  no1  be  used, 
and  indirect  methods  must  be  resorted  to. 

The  "wire  method"  has  been  described  first  in  this  paper,  as  it  is 
best  suited  to  field  work.  Besides  this  method,  there  are  two  others 
that  have  commended  themselves  to  practical  use.  First,  the  use  of 
standards  of  comparison;  second,  the  diaphanometor." 

In  the  determinations  of  turbidity  of  waters  in  rivers  considered  in 
this,  paper,  the  turbidities  were  in  general  too  low  for  accurate  measure- 
ments by  the  wire  method,  and  as  the  samples  had  to  be  shipped  to 
the  laboratory  for  other  determinations,  the  turbidity  was  found  by 
comparison  with  standards.    These  standards  were  made  up  from  dia- 


«  These  are  both  laboratory  methods,  and  have  been  described  by  Mr.  George  C.  Whipple  and 
Daniel  D.Jackson,  in  the  Technology  Quarterly,  Vol.  XII,  No.  4,  December,  1899. 


PRESSEY.  ] 


COLOR. 


78 


tomaceous  earth  thoroughly  washed  and  ignited  to  remove  the  organic 
matter.  The  earth  is  then  washed  in  hydrochloric  acid  an<l  rinsed 
with  water,  after  which  it  is  pulverized.  One-half  grain  is  added  to 
500  e.  c  of  distilled  water  and  thoroughly  agitated.  This  stock  mix- 
ture contains  1  grain  of  pure  silica  per  liter,  or  L,000partsper  1,000,000, 
and  when  well  shaken  will  always  give  the  same  turbidity,  which  is 
called  a  standard  1,000.  For  waters  of  low  turbidities,  Like  those 
found  in  New  York  State,  standards  are  made  by  diluting  the  stock 
mixture  with  distilled  water  in  measured  proportions  and  comparing 
the  collected  samples  with  the  various  standards  in  gallon  bottles, 
while  with  higher  turbidities  smaller  quantities  of  the  standards  are 
placed  in  100c.  c.  Nessler  tubes,  with  which  the  samples  in  Like  tubes 
are  compared.  This  is  a  laboratory  method,  and  is  more  precise  than 
the  wire  method  of  making  determination  of  turbidity,  but  requires 
that  samples  be  collected  and  shipped  to  the  laboratory. 

In  order  that  some  idea  of  the  meaning  of  the  various  standards  may 
be  obtained,  the  following  table  is  inserted: 


Table  showing  meaning  of  various  numbers  on  silica  scale. 


Silica  standard. 

Destriptive  term. 

0  

1-2    

None. 

Very  slight. 
Slight. 
Distinct. 
Decided. 

2-5    

5-20  

Above  30  _  ,  3?..  

COLOR. 


The  platinum-cobalt  method  of  measuring  color,  as  devised  by  Allen 
Hazen,  is  generally  considered  the  standard. 

A  standard  solution  which  has  a  color  of  500  shall  be  made  by  dis- 
solving 1.246  grams  potassium-platinic  chloride"  (PtCl4,2KCl),  con- 
taining 0.5  gram  platinum,  and  1  gram  of  crystallized  cobalt  chloride 
(CoCl?,6H30),  containing  0.25  gram  of  cobalt  in  water,  with  100 
cubic  centimeters  concentrated  hydrochloric  acid,  and  making  up  to 
1  Liter  with  distilled  water.  By  diluting  this  solution  standards  shall 
be  prepared  having  values  of  0,  5,  10,  15,  20,  25,  30,  35,  40,  50,  GO,  and 
70.  The  numbers  correspond  to  the  metallic  platinum  in  the  solu- 
tions in  parts  per  million.  These  shall  be  kept  in  100-cubic-centimeter 
Nessler  jars  of  such  diameter  that  the  Liquid  shall  have  a  depth 
between  20  and  25  cent  imeters  and  shall  be  protected  from  dust .  The 

"Potassium-platinous  chloride  is  a  salt  that  is  often  substituted  by  dealers  in  place  of  the 
potassium-platimc  chloride.  It  is  sometimes  incorrectly  labeled.  The  platinous  salt  has  a  red- 
dish color  while  the  platmic  salt  has  a  yellow  eoloi . 


74 


FLOW  OF  EIVEKS  NEAR  NEW   YORK  CITY. 


color  of  a  sample  slrall  be  observed  by  filling  a  similar  lube  with  water 
and  comparing  it  with  the  standards.  The  observation  shall  be  made 
by  looking  vertically  downward  through  the  tubes  upon  a  white  sur- 
face placed  at  such  an  angle  that  lighl  is  reflected  upward  through 
the  column  of  Liquid.  The  reading  shall  be  recorded  to  the  nearest 
unit.  Waters  thai  have  a  color  darker  than  70  shall  be  diluted  before 
making  the  comparison,  in  order  that  no  difficulties  maybe  encoun- 
tered in  matching  the  hues.  Water  containing  matter  in  suspension 
shall  be  filtered  until  no  visible  turbidity  remains.  If  the  suspended 
matter  is  coarse,  filter  paper  may  be  used  for  this  purpose;  if  the  sus- 
pended matter  is  fine,  the  use  of  the  Berkfeld  filter  is  recommended, 
but  it  must  be  thoroughly  washed  each  time  before  using.  The  use 
of  a  Pasteur  filter  is  to  be  avoided,  as  it  exerts  a  decolorizing  action. 

The  determinations  of  color  upon  the  streams  considered  in  this 
paper,  and  gi\Ten  on  the  following  pages,  were  made  by  the  above 
laboratory  method.  For  the  sake  of  completeness,  however,  the  field 
method  of  making  determinations  of  color  will  be  described. 

It  is  impracticable  to  carry  the  standard  tubes  above  described  into 
the  field  for  observations,  and  yet  field  observations  are  of  great  con- 
venience and  value  to  the  sanitary  engineer,  and  in  general  to  the 
investigations  of  the  United  States  Geological  Survey. 

Standard  disks  of  colored  glass  have  been  prepared  by  Mr.  Allen 
Hazen,  in  cooperation  with  the  Survey,  as  standards  for  measuring 
color  of  water  in  the  field  (PI.  X).  These  disks  have  been  rated  by 
Mr.  George  C.  Whipple  to  correspond  with  the  platinum-cobalt  stand- 
ard. The  color  is  measured  by  balancing  the  color  of  the  water  in  a 
metallic  tube  with  glass  ends  against  the  colors  of  glass  disks  of 
known  value.  The  number  on  each  disk  represents  the  correspond- 
ing color  of  a  water.  This  is  not  a  new  standard,  but  a  new  applica- 
tion of  an  old  standard.  The  glass  disks  are  rated  to  correspond 
with  the  platinum-cobalt  color  standard.  The  process  bears  the  same 
relation  to  the  usual  Laboratory  process  that  an  aneroid  barometer 
bears  to  a  mercurial  barometer.  The  metallic  tubes  and  glass  stand- 
ards are  more  portable  and  better  adapted  to  field  use  than  the  Xesslei 
tubes  and  color  solutions  previously  used. 

Color  standards. — The  standards  are  disks  of  amber-colored  glass, 
mounted  with  aluminum.  Eacli  disk  carries  two  [lumbers.  One 
number  is  over  100,  and  is  a  serial  number  for  the  purpose  of  identi- 
fiealion.  The  other  number  is  less  than  100,  and  shews  the  color, 
value  of  the  disks;  that  is  to  say,  the  color  of  each  disk  is  equal  to 
the  color  of  a  solution  of  the  designated  number  of  parts  piW  million 
of  platinum  with  the  required  amount  of  cobalt  to  match  the  hue 
when  seen  in  a  depth  of  200  millimeters. 

Kaeh  apparatus  has  a  series  of  glass  disks  of  varying  v  alues,  sol 
that  waters  within  a  reasonable  range  can  be  matched  by  them.] 
When  a  water  conies  between  two  disks  its  value  can  be  estimated 


• 

o 

Fiihklll 
Wallkill 
Eiopui 
Cattklll 

•  

gg   

©    Tenmile 

a  Rondout 
■  Houtatonlc 

• 

• 

- 

1 

0 

■ 

A 

j 

-eJp  

e  B 

 l4 

— y — 
/ 

e 

Z     •  ' 
.-•  "  "  " 

/ // 

etf/  

8$  a* 

0 

So  d 

• 

PRESSEY.] 


COLOR. 


75 


between  tliem  by  judgment.  Two  or  more  disks  can  be  used,  one 
behind  the  other,  in  which  case  their  combined  value  is  the  sum  of 
the  individual  values.  By  combining  the  disks  of  a  series  in  different 
ways  a  considerable  number  of  values  can  be  produced,  allowing  the 
closer  matching  of  many  waters. 

Filling  the  tubes. — The  tube,  having  an  aluminum  stopper,  is  to  be 
filled  with  water,  the  color  of  which  is  to  be  determined.  Rinse  the 
tube  once  or  twice  by  filling  and  emptying  it.  The  second  tube,  having 
the  clips  to  hold  the  glass  disks,  is  made  much  like  the  one  holding 
the  water  to  facilitate  comparison.  Theoretically  this  tube  should  be 
filled  with  distilled  water.  Practicall}r  it  makes  very  little  difference 
whether  it  is  filled  with  distilled  water  or  empty.  Use  distilled  water 
when  it  is  convenient  to  do  so,  and  when  distilled  water  of  unques- 
tionable quality  is  at  hand;  otherwise  wipe  the  inside  of  the  tube 
dry  to  prevent  fogging  of  the  glass  ends,  and  proceed  with  the  tube 
empty. 

Holding  the  tubes. — Hold  the  tubes  at  such  a  distance  from  the  eye 
that  the  sides  of  the  tubes  just  can  not  be  seen.  This  occurs  when  the 
near  end  of  the  tube  is  8  or  9  inches  from  the  eye.  Hold  the  tubes  at 
such  an  angle  that  both  can  be  seen  at  once  with  one  eye.  Good 
results  can  not  be  obtained  in  any  other  way.  Let  the  tubes  change 
places  once  or  twice,  as  sometimes  the  light  on  the  right  and  left  is 
not  quite  equal. 

Background. — There  should  be  a  clear  white  background  with  a 
strong  illumination.  The  best  results  can  not  be  obtained  with  either 
too  little  or  ^oo  much  light.  In  a  gray  day  look  at  the  sky  near  the 
horizon  and  away  from  the  sun.  In  a  bright  day  look  at  a  piece  of 
white  paper  or  tile,  upon  which  a  strong  light  falls.  The  white  sur- 
face may  be  vertical  and  the  tubes  held  horizontally,  or  the  tubes  may 
be  held  at  an  angle  directed  downward  toward  a  horizontal  surface, 
as  may  be  most  convenient.  Good  results  can  not  be  obtained  by 
artificial  light. 

Turhid  water. — The  colors  of  very  turbid  waters  can  not  be  meas- 
ured in  this  way.  Slight  turbidities  do  not  interfere  seriously  with 
the  results.  Waters  too  turbid  for  direct  observations  should  be  fil- 
tered through  thick  filter  paper  before  being  tested,  and  in  case  1  he 
turbid  matter  is  fine  and  in  large  amount  even  this  method  may  fail. 
The  turbidity  of  water  should  be  taken  as  far  as  possible  in  connection 
with  color  observations,  except  in  cases  where  it  is  obvious  from 
inspection  that  there  is  practically  no  turbidity. 

Highly  colored  waters. — Some  waters  will  be  found  having  a  higher 
color  than  can  be  matched  by  the  standards.  In  general,  waters  with 
colors  above  100  should  not  be  matched  in  200-millimeter  t  iibes,  and  t  he 
results  with  waters  having  colors  below  80  will  be  considerably  more 
accurate  than  with  more  highly  colored  ones.  Two  procedures  are 
possible  with  waters  having  higher  colors — namely,  to  dilute  with  dis- 


76  FLOW   OF   RIVERS   NEAR  NEW   YORK   CITY.  [no. 76. 

tilled  water  before  measuring  the  color  or  to  use  shorter  tubes.  The 
hitter  procedure  is  the  more  convenient,  but  both  are  equally  accu- 
rate. To  measure  the  color  with  short  tubes,  put  the  highly  colored 
water  in  a  tube  of  one-half  the  usual  length  and  match  as  usual.  It 
is  not  necessary  to  have  a  short  standard  holder.  The  200-millimeter 
tube  can  be  used.  After  the  water  is  matched  the  result  is  multiplied 
by  2.  In  case  the  color  is  too  high  to  be  read  in  a  100-millimeter  tube 
it  can  be  put  in  a  50-millimeter  tube,  and  the  result  multiplied  by  4. 
When  dilution  is  used  the  highly  colored  water  is  mixed  with  one  or 
more  volumes  of  distilled  water,  the  color  matched,  and  the  result 
multiplied  by  a  corresponding  factor.  The  tube  itself  can  be  used 
for  measuring  the  colored  water  and  the  distilled  water,  and  the  mix- 
ing can  be  done  in  a  tumbler  or  any  convenient  clean  vessel. 

Cleaning  the  tubes. — The  tubes  should  always  be  kept  clean  and 
the  glass  ends  protected.  All  the  ends  are  removable  for  the  purpose 
of  cleaning,  and  should  not  be  screwed  on  too  tightly.  They  should 
be  water-tight  -when  only  screwed  up  loosely,  and  if  screwed  on  hard 
they  may  stick  so  as  to  come  otf  with  difficulty. 

ALKALINITY. 

The  alkalinity  of  water  is  practically  a  measure  of  the  carbonates 
and  bicarbonates  present.  The  determination  is  made  as  follows: 
Put  100  c.  c.  of  the  sample  into  a  6-inch  porcelain  evaporating  dish. 
Add  two  or  three  drops  of  a  0.1  per  cent  aqueous  solution  of  methyl- 
orange.  If  the  water  is  alkaline,  this  will  impart  to  it  a  faint  yellow- 
ish brown  color.  Then  from  a  burette  graduated  in  tenths  of  a  cubic 
centimeter  run  in  a  fiftieth-normal  solution  of  sulphuric  acid  until  the 
color  of  the  water  changes  to  a  faint  pink.  The  acid  must  be  added 
in  small  portions  (only  one  drop  at  a  time  as  the  end  point  is  reached) 
and  the  water  stirred  with  a  glass  rod  after  each  addition.  The  num- 
ber of  cubic  centimeters  of  fiftieth-normal  acid  required,  when  multi- 
plied by  ten,  gives  t lie  alkalinity  of  the  water  expressed  in  equivalent 
parts  per  million  of  calcium  carbonate.  That  is,  if  1.8  c.  c.  is  required 
to  cause  the  color  of  the  indicator  to  change  from  brown  to  red,  then 
the  alkalinity  of  the  water  is  18  parts  per  million.  Inasmuch  as  it 
is  necessary  to  add  a  certain  amount  of  fiftieth-normal  acid  to  100  c.  c. 
of  water  which  has  no  alkalinity  in  order  to  produce  the  typical  color 
change,  the  reading  obtained  must  ho  corrected  for  this  amount.  This 
correction  for  the  indicator  varies  with  different  individuals,  but  it 
seldom  exceeds  I  >.3  C.  C. 

Other  indicators,  such  as  lacmoid  or  erythrosine,  may  be  used  in 
place  of  methyl-orange,  and  in  certain  instances  their  use  is  to  be  pre- 
ferred, but  for  general  field  work  methyl-orange  is  most  convenient. 

PERMANENT  HARDNESS. 

The  Clark's  soap  method  has  been  used  in  the  examinations  of  river 
waters  given  in  the  following  tables.    This  method  gives  reliable 


0.      .    Fishkill  ** 

0  Wallkill 

•  Esopus 

B  Catskill 

©  Tenmile 

O  Rondout 

c 

Q  Housaton 



- — 

3 

ui 

•» 

t 

a 

0 

i 

\ 

 r 

\ 

0 

\ 

• 

\  © 

1  i  * 

\  ^ 

1  i  0 

-\4  

i 

s 

a 

\ 

\ 

o 

□ 

— 

<'// 

_»  id  

 0  

 ©  ■ 

e 

-o.« 

i  a 

)  0 

■-*- 

o  ^~ 
U-EUa— b- 

— O-o 

H 

-S-o 

a> 

— e-css 

Alkalinity 

DIAGRAM  SHOWING  RESULTS  OF  ALKALINITY  OBSERVATIONS. 


PKESSKY.] 


QUALITY   OF  RIVER  WATER. 


77 


results  for  waters  as  soft  as  those  under  consideration,  I  ml  for  the 
hard  waters  of  the  Central  States  Hehner's  acid  method  will  perhaps 
give  more  reliable  and  uniform  results. 

Results  of  determinations  of  hardness  obtained  by  various  observ- 
ers are  frequently  very  discrepant,  and  it  is  not  uncommon  to  have 
results  reported  by  chemists  which  are  worthless  on  account  of  faulty 
methods.  Tt  is  hoped  that  the  determinations  of  hardness  may  he  made 
upon  a  more  uniform  basis  throughout  the  country,  so  I  hat  the  results 
may  be  comparable. 

In  the  following  tables  are  given  the  results  of  the  observations  upon 
turbidity,  color,  alkalinity,  and  hardness,  together  with  the  discharge 
of  Esopus,  Rondout,  WallMU,  Catskill,  Fishkill,  Tenmile,  and  Housa- 
tonic : 

Turbidity  color,  alkalinity,  and  hardness  of  streams. 


CATSKILL  CREEK. 


Date. 

Gage 
height. 

Color. 

Turbid- 
ity. 

Alkalin- 
ity. 

Hard- 
ness. 

Discharge  in 
second-feet. 

1901. 

Aug.  19  _  _ . 

«2.62 

6 

1 

58.0 

28 

Aug.  27  _ 

a  2. 95 

11 

•  2 

48.0 

77 

Sept.  2  

«3.00 

i 

2 

53.0 

89 

Sept.  8  

«  2. 90 

9 

2 

55.0 

66 

Sept.  23  

2.73 

2 

2 

54.0 

39 

Oct.  4  

2.70 

\ 

1 

51.0 

36 

Oct.  10  # 

2.65 

1 

53.0 

53.0 

31 

Oct.  22  

"  2.82 

6 

3 

50.0 

51 

Nov.  8  

2.70 

1 
3 

49.0 

50.0 

36 

Nov.  19  

2.75 



1 

50.0 

50.0 

42 

Dec.  9  

3.30 

2 

38.0 

44.5 

110 

1902. 

Jan.  15  

3.50 

2 

1 

38.0 

42.0 

144 

Feb.  27... . 

4.90 

22 

11 

25.0 

26.0 

400 

Apr.  10  _  _ . 

6.70 

22 

25 

22.0 

24.0 

2,200 

May  10.... 

3.47 

4 

6 

36.0 

42.0 

133 

June  3   . 

2.82 

6 

1 

42.0 

50.0 

99 

June  24    

2.70 

9 

3 

47.0 

51.5 

43 

July  9  I  

3.40 

9 

2 

45.0 

47.0 

113 

July  23   

6.11 

35 

25 

35. 0 

44.5 

1 , 602 

Aug.  2  . 

5.36 

33 

12 

42.0 

49.0 

1.005 

Aug.  13  

3.49 

12 

1 

50.0 

50.  5 

135 

Aug.  27  

2.74 

11 

4 

56. 0 

52.  0 

394 

Sept.  5   

2.79 

6^ 

4 

56.0 

56. 0 

50 

"Taken  from  gage  height  record. 


78  FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY.  [no. TO. 

Turbidity,  color,  alkalinity,  and  hardness  of  streams — Continued. 


RONDOUT  CREEK. 


Date. 

Gage 
height. 

Color. 

Turbid- 
ity. 

Alkalin- 
ity. 

Hard- 
ness. 

Discharge  in 
second-feet. 

1901. 

Aug.  28 

7. 15 

42 

4 

37.0 

620 
980 

Sent.  1 

7.62 

32 

20 
6 

23.0 

Sept.  3  

7.80 

66 

11.0 

1, 126 

Sent.4   

7. 13 

68 

15 

18.0 

602 

Sept.  19 

6.87 

30 

12 

18.0 

430 

Do 

6.87 

30 

13 

14.0 

430 

Ort.  1 1 

6.50 

26 

4 

17.0 

185 

Oct.  3 

6.95 

40 

4 

22.0 

22.0 

481 

Oct.  15 

7.65 

26 

8 

22.0 

«21.0 

1,001 

Oof  00 

6.70 

28 

3 

20.0 

« 19. 0 

314 

Oct.  31 

6.50 

24 

4 

24.0 

«  24. 0 

185 

Nov.  13 

7.00 

21 

14 

26.0 

27.0 

515 

Nov  16 

6.60 

26 

5 

20.0 

26.0 

249 

Nov  19 

6.40 

21 

2 

20.0 

24.0 

123 

Nov  oc> 

6.35 

23 

3 

19.0 

25.0 

92 

Nov.  26 

7.30 

32 

17.0 

23.0 

728 

Nov  29 

6.80 

31 

3 

21.0 

24.0 

380 

Dec  3 

6.40 

23 

21.0 

24.5 

123 

Dec  6 

6.80 

21 

3 

19.0 

23.5 

280 

Dec.  10 

9.80 

32 

65 

19.0 

25.0 

1,700 

Dec.  11 

9.50 

38 

'  (6) 

13.0 

20.0 

2, 650 

Dec.  12 

8.50 

34 

19 

12.0 

17. 5 

1,750 

16.70 

80 

(6) 

13.0 

18.0 

12, 230 

Dec.  16 

11.00 

48 

75 

11.0 

20.0 

4, 250 

Dec.  25 

7.25 

13 

7 

14.0 

26.0 

592 

12.20 

32 

60 

10.0 

20.0 

5, 574 

1902. 

Jan.  7 

7. 00 

17 

5 

14.0 

24.0 

515 

Jan. 14 

6. 70 

14 

4 

20.0 

23.5 

240 

Jan.  18 

6. 70 

14 

3 

18.0 

21.0 

240 

10.30 

32 

3 

10. 0 

12.5 

3, 480 

7.90 

23 

1 

12.0 

14.5 

1,212 

Jan.  28 

7.70 

80 

10 

21.0 

25.5 

0:5 

Feb.  4 

9.50 

14 

18 

14.5 

21.5 

2, 650 

Feb.  11 

8.  20 

11 

11 

19.5 

24.5 

900 

Feb.  14 

7.85 

10 

6 

20.0 

24.  5 

742 

Feb.  27 

10.45 

22 

30 

13.0 

15.9 

2,000 

"  Likely  too  low.  *> Bottle  broken 


0 

0         .     ._  Fishkill 

s 

O  Wallkill 

B 

 f!atil<ill 

c 
e 

  r< 

  R 

ndout' 

□  H 

1 

i 

ondn.it 

t 

J 

n 

i 

i 

— r 
i 

I 

•  1 

I 

. 

c 

? 

\ 

i 

\ 
\ 

-\— 

e 

5 

\ 
\ 

\ 

o 

\ 

\ 

\ 

\ 

I 

I 

-4— 

\  N 

—  r" 

-4 

is 

\ 

\ 

 X 

N 

i 

o  i 

\ 

N 

i 

•  i< 

4 

\ 

o 

tski/l 

^-8 

. 

Hardness. 

(DIAGRAM  SHOWING  RESULTS  OF  HARDNESS  OBSERVATIONS. 


pressey]  QUALITY  OF  RIVER  WATER.  79 

Turbidity,  color,  alkalinity,  and  hardness  of  streams— Continued. 


RONDOTT  ( 'REEK  Continued. 


Date. 

height. 

Color. 

Turbid- 
ity. 

Mkalin- 
ity. 

Hard- 
ness. 

Discharge  in 
second-feet. 

1902. 

Mar.  1  

17.  55 

42 

145 

14.0 

14.3 

13, 900 

Mar.  2  

14.00 

40 

120 

14.5 

13.  5 

7, 900 

Mar.  3  

11.75 

31 

55 

11.0 

11.9 

5,075 

Mar.  4  

'  9.  90 

21 

30 

9.5 

12.0 

3,043 

Mar.  8  

7.  75 

30 

28 

14.0 

16.  5 

1,084 

Mar.  9  

12.70 

35 

48 

12.  5 

15.  0 

6, 120 

Mar.  9  

9.  50 

19 

50 

14.0 

21.0 

2,650 

Mar.  10  

10. 00 

23 

80 

12. 5 

19.  5 

3. 150 

Mar.  29  

11.00 

25 

40 

14.0 

19.0 

4,250 

Apr.  8  

7.65 

21 

15 

13.0 

17.0 

1,000 

Apr.  10  

11.95 

32 

32 

12.0 

14.0 

5,665 

Apr.  24  _  

6.90 

14 

4 

18.0 

22.0 

447 

Apr.  26  

7.10 

16 

35 

15. 5 

20.  5 

■  585 

Apr.  30  

9.30 

25 

28 

13.5 

19.0 

2,470 

May  26  

6.90 

12 

•  8 

23.0 

24.5 

447 

May  28  

7.10 

14 

21 

23.0 

24.5 

585 

June  5   .  

6.45 

14 

18 

27.0 

28.0 

156 

June  6  . .   

6.40 

13 

7 

23.0 

25.0 

163 

June  18  

6.  50 

13 

10 

28.0 

30.0 

185 

June  19  f  

6. 30 

13 

14 

32.0 

32.5 

75 

June  22  

7.20 

12 

20 

25.0 

31.2 

656 

June  28  

7. 55 

21 

24 

20.  5 

24.7 

920 

6.80 

31 

30 

21.5 

22.8 

380 

July  19  

6.30 

15 

2 

27.0 

30.5 

75 

July  21  .... 

8.65 

40 

95 

21.0 

22.0 

1,885 

July  22  

9.  75 

35 

105 

15.0 

19.  5 

2,890 

July  23.   

8.60 

45 

35 

13.0 

17.0 

1,840 

July  26  

9. 85 

45 

45 

15.0 

24.0 

2,991 

July  31    

7.35 

30 

14 

14.0 

24.0 

765 

Aug.  7 . .   

7.39 

28 

8 

19.0 

26.0 

838 

Aug.  13  

6.80 

17 

2 

18.0 

£2.0 

380 

Aug.  15   

6. 50 

ia 

1 

22.0 

22.5 

185 

6.40 

20 

2 

24.0 

28.0 

123 

Aug.  21  

6.35 

16 

2 

25.  0 

27.  0 

92 

6.  25 

11 

5 

23.0 

24.5 

60 

Aug.  27  

6.30 

14 

13 

30.0 

29.  0 

75 

Aug.  30   

6.  35 

12 

5 

26.0 

27.  5 

-92 

Sept.  5  

6.  10 

11 

4 

26.0 

31.0 

35 

80  FLOW  OF  RIVERS  NEAR  NEW   YORK  CITY.  [no. 76. 

Turbidity,  color,  alkalinity,  and  hardness  of  streams — Continued. 


*-    RONDOUT  CREEK— Continued. 


Date. 

(Stage 
height. 

Color. 

Turbid- 
ity. 

Alkalin- 
ity. 

Hard- 
ness. 

Discharge  in 
second-feet. 

1902. 

Sept.  8  

6.20 

11 

2 

28.0 

31.0 

SO 

Sept.  11  

6.  50 

14 

6 

23.0 

24.  5 

185 

Sept.  16  

6. 30 

17 

3 

23.0 

26.0 

75 

Sept.  17  

6.20 

17 

3 

23.0 

28.0 

50 

ESOPUS  CREEK. 


1901. 

Aug.  25  

7.67 

52 

35 

17.5 

(«) 

1,200 

Aug.  27  .  

6.02 

34 

7 

22.0 

540 

Aug.  29  

5.  72 

28 

3 

430 



Sept.  4  

6.27 

19 

13 

19.0 

640 

Sept.  21  

4.78 

11 
9 

3 

23.0 

198 

Sept.  26  

4. 55 

4 

23.5 

167 

Oct.  3  

5.25 

16 

6 

18.0 

295 

Oct.  8  

4.70 

14 

3 

18.0 

188 

Oct.  17  

6.30 

14 

10 

14.0 

15.  0 

650 

Nov.  1  

4.75 

9 

4 

15.0 

18.0 

195 

Nov.  14  

4.75 

9 

4 

21.0 

22.0 

195 

Nov.  18  

4.45 

9 

2 

17.0 

22.0 

153 

Dec.  4  

5.30 

10 

6 

16.0 

20.5 

223 

Dec.  11  

Mi.  40 

45 

38 

10.  0 

16.0 

1,721 

Dec.  19  

8. 35 

22 

50 

22.5 

19.0 

1.470 

Dec.  30  

12.10 

25 

80 

11.0 

17.0 

3,723 

1902. 

Jan.  9  

6.50 

15 

15 

13.0 

21  0 

514 

Jan.  22  

16.00 

29 

180 

10.0 

15  0 

7, 600 

Feb.  7  

6.80 

16 

20 

15.0 

19.  5 

628 

Feb.  20  

5.35 

8 

5 

19.0 

23. 5 

231 

Mar.  1   

20.40 

48 

180 

11.0 

16.5 

12, 600 

Mar.  12  _____ 

9.90 

25 

125 

18. 5 

23.  5 

2, 843 

Apr.  10  

13.25 

22 

35 

9.0 

13.5 

5.021 

6.94 

16 

21 

13.0 

15.0 

910 

May  14*.              _  _  

5.83 

12 

10 

16.0 

20.  0 

474 

May  24   

5.02 

8 

4 

19.0 

24.0 

83a 

June  5  _  

5.  03 

14 

17 

20.  0 

22.  5 

2.345 

June  10  .  

4.48 

10 

5 

24.0 

26.0 

1 , 358 

June  26   

5.  00 

18 

13 

20.  0 

22.  0 

2,312 

"From  Aug.  86  to  Oct.  8,  hardness  not  determined.  ''Backwater. 


PRESSEY.] 


QUALITY   OF  RIVEK  WATER. 


81 


Turbidity,  color,  alkalinity,  and  hardness  of  streams — Continued. 
ESOPUS  CREEK-Continued. 


Date. 

Gage 
height. 

Color. 

Turbid- 
ity- 

Alkalin- 
ity. 

Hard- 
neSS. 

Discharge  in 
second-feet. 

1902. 

July  9 

5. 80 

20 

12 

16.0 

27.5 

4, 504 

July  16 

5. 13 

10 

10 

18. 0 

27.  5 

2, 688 

July  24 

8.11 

35 

15 

15.0 

•  28.  5 

1.348 

July  30 

7.65 

23 

8 

14.0 

24.0 

1.  155 

Aug.  12 

6.28 

21 

8 

24.  0 

26.  5 

550 

Aug.  21 

4.94 

14 

6 

23.0 

25.  5 

191 

Sept.  4 

4.49 

11 

6 

34.0 

31.0 

133 

1901. 


Aug.  17 
Aug.  20 
Aug.  23 
Aug.  24 
Aug.  28 
Aug.  31 
Sept.  5  . 
Sept.  19 
Oct.  9  . . 
Oct.  31  . 
Nov.  9  . 
Nov.  16 
Dec.  11. 
Dec.  19. 
Dec.  30. 

Jan.  13  . 
Jan. 23  . 
Feb.  10. 
Feb.  24 
Mar.  10 
Apr.  21 . 
May  1  . . 
May  21  . 
June  6 
July  17. 
July  29. 


1902. 


WALLKILL  RIVER. 


6.  75 

78 

3 

77.0 

565 

7.2 

110 

9 

48.5 

794 

6.25 

104 

6 

58.0 

321 

6.05 

110 

'  12 

64.0 

232 

5.85 

82 

14 

62.  0 

...  .. 

165 

5.95 

86 

12 

71.0 

196 

8.55 

82 

12 

65.0 

1,503 

7.30 

45 

13 

59.0 

814 

6.  50 

60 

7 

67,0 

440 

6.10 

46 

5 

81.0 

93.0 

264 

5.94 

28 

4 

92.0 

105.0 

202 

6.50 

45 

9 

88.0 

97.0 

440 

all.  50 

60 

45 

43.0 

50.0 

2,480 

13.70 

55 

38 

37.0 

42.0 

3,680 

20.20 

35 

45 

24.0 

26.0 

8.190 

8.  05 

33 

15 

74.0 

83.0 

717 

10.40 

38 

125 

25. 0 

30.0 

5.422 

7.78 

21 

14 

67.0 

76.0 

596 

7.30 

19 

10 

89.0 

97.2 

382 

10.40 

31 

160 

26. 0 

31.0 

5.422 

7 .  55 

29 

25 

56.  0 

60.0 

977 

10.00 

*  (50 

28 

44.0 

46.0 

•J.  5  10 

6.  33 

39 

8 

75.0 

89.0 

356 

6.  40 

20 

13 

73.0 

84.0 

381 

5.  70 

33 

I 
.) 

82. 0 

90.0 

126 

7.49 

52 

23 

54. 0 

72.0 

942 

Backwater. 


1KB  7(5— 03- 


82  FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY.  [no. 76. 


Turbidity,  color,  alkalinity,  and  hardness  of  streams — Continued. 
'WALLKILL  RIVER— Continued. 


Date. 

Gage 
height. 

Color. 

Turbid- 
ity. 

Alkalin- 
ity. 

Hard- 
ness. 

Discharge  in 
second-feet. 

1902. 

Aug.  6 

7.98 

68 

25 

62.0 

71.0 

1,150 

Aug.  15 

6.72 

48 

8 

83.0 

84.0 

518 

Aug.  28 

5. 86 

24 

5 

88.0 

89.0 

169 

Sept.  6 

5.  78 

38 

5 

57.0 

61.0 

145 

TENMILE  RIVER. 


1901. 

Sept.  12 

5.  90 

13 

2 

121.0 

364 

Oct.  26 

5.00 

12 

4 

134.  0 

142.0 

166 

Nov.  11 

4.75 

8 

2 

146.0 

151.0 

120 

Nov.  22 

4.80 

8 

2 

147.0 

154. 0 

129 

Dec.  2 

4.75 

6 

1 

137.0 

152.5 

120 

Dec.  17 

8.41 

25 

12 

79.0 

86.0 

1, 120 

Dec.  27 

6.54 

22., 

9 

103.0 

106.0 

524 

1902. 

Jan.  10 

5.75 

11 

4 

98.0 

103.0 

328 

Feb.  4 

6.30 

13 

11 

90.0 

104.0 

460 

Feb.  13 

5.00 

8 

6 

126.0 

137.0 

166 

Mar.  3 

a  10. 41 

21 

36 

60.0 

61.1 

&2,100 

Apr.  7 

«  6.  18 

12 

3 

100.0 

103.0 

558 

May  2 

6.  46 

19 

7 

105.0 

112.0 

640 

May  15 

4.  88 

12 

1 

118.0 

123.0 

230 

June  9 

4. 44 

16 

15 

130.0 

139.0 

122 

June  30 

4.90 

19 

6 

133.0 

160.0 

249 

July  21 

7.20 

40 

25 

88.0 

90.0 

821 

Aug.  4 

4.69 

11 

3 

129.0 

141.0 

1,848 

Aug.  19 

4.28 

10 

4 

138.0 

160.0 

100 

Sept.  2 

3. 95 

10 

4 

139.0 

155.0 

63 

FISHKILL  CREEK. 

1901. 

Aug.  21 

c4.45 

39.0 

2 

88 



286 

Aug.  31 

c4.57 

24.0 

4 

85 

335 

Stmt  4 

<-4.42 

24.0 

6 

88 

277 

3.90 

13.0 

3 

82 

93.0 

113 

«  All  readings  on  this  and  following  dates  made  on  new     &  Approximate. 

gage  placed  0.33  foot  higher  than  the  old  gage.  o  Taken  from  daily  gage  height  record. 


PKESSEY.] 


QUALITY  OF  RIVER  WATER. 


83 


Turbidity,  color,  alkalinity,  and  hardness  of  streams — Continued. 
FISHKILL  CREEK— Continued. 


Dat. 


1901. 


Oct. 

Oct. 

Oct. 

Oct. 

Nov. 

Nov. 

Nov. 

Nov. 

Nov. 

Nov. 

Nov. 

Dec. 

Dec. 

Dec. 

Dec. 

Dec. 

Jan. 
Jan. 
Jan. 
Jan. 
Jan. 
Jan. 
Jan. 
Jan. 
Feb. 
Feb. 
Feb. 
Feb. 
Feb. 
Mar. 
Apr. 
Apr. 
Apr. 
Apr. 
May 
May 
Mav 


10  , . 
17 

25  . 
31  . . 

5  -  _ 

8 

13  . 
15  _ 
19  . 
23  . 
26  . 
17_ . 
19.. 
24.  _ 
26. . 
31.. 


1902. 


15. 
20. 

09 


a  Likely  too  low. 


age 
ight. 

( '<  >1<  >r. 

Turbid- 
ity. 

ATkaHn- 
ity. 

Hard- 
ness. 

Discharge  in 
second-feet. 

3. 85 

11.0 

2 

94 

100.0 

100 

4. 50 

36.0 

4 

72 

"  68. 0 

305 

4.05 

16.0 

2 

88 

a  84. 0 

154 

4.00 

12.0 

3 

87 

89.0 

140 

3.90 

12.  0 

5 

85 

89.0 

113 

3.  95 

11.0 

4 

85 

92.0 

500 

4.35 

17.0 

4 

80 

87.0 

250 

4.05 

21.0 

4 

• 

78 

109.0 

154 

3.95 

13.0 

4 

79 

94.0 

126 

3.  90 

8.0 

4 

83 

89.0 

113 

4.30 

22.0 

5 

74 

84.0 

233 

6.10 

29.0 

12 

45 

•    47. 0 

926 

5.  10 

21.0 

7 

58 

64.0 

409 

4.  55 

11.0 

5 

71 

78.0 

224 

4.55 

13.0 

4 

74 

79.0 

224 

7.30 

24.0 

12 

33 

39.  0 

1,682 

5.  65 

15. 0 

7 

52 

60.0 

673 

4.80 

12.0 

3 

66 

78.0 

300 

4.65 

11.  0 

2 

70 

81.0 

&253 

5.00 

5. 0 

3 

79 

83.0 

&370 

4.35 

6.0 

5 

79 

85.0 

&172 

4. 15 

6.  0 

3 

82 

85.0 

&128 

4.  90 

30.0 

25 

52 

55 .  5 

*>334 

4.95 

9.0 

4 

63 

77.0 

6  352 

5.  50 

13. 0 

53 

60. 0 

&594 

5.20 

11.0 

6 

72 

82.0 

640 

4.80 

7.  0 

4 

74 

81.0 

430 

4. 40 

5. 0 

6 

80 

86. 0 

268 

4.40 

7. 0 

11 

79 

87.0 

268 

5. 20 

11.0 

14 

48 

60. 0 

640 

1  (50 

10  0 

o 

uo 

fitf  0 
uo.  u 

4.30 

9.5 

4 

70 

72.0 

233 

4.10 

11.0 

3 

72 

76.  0 

169 

4.00 

13.0 

3 

79 

82.0 

140 

3.90 

11.0 

4 

74 

85.0 

113 

3.80 

11.0 

3 

76 

85.0 

88 

3.70 

13.0 

2 

79 

85.0 

66 

''Taken  from  daily  gage  height  record. 


84 


FLOW   OF  RIVERS  NEAR  NEW   YORK  CITY. 


fwo.76. 


Turbidity,  color,  alkalinity,  and  hardness  of  streams — Continued. 
*-  FISHKILL  CREEK— Continued. 


Date. 

Gage 
heignt. 

Color. 

Turbid- 
ity. 

Alkalin- 
ity: 

Hard- 
ness. 

Discharge  in 
second-feet. 

1902. 

May  28  

4.55 

34.  0 

5 

70 

80. 0 

405 

June  6 

3,  50 

11.0 

3 

TO 

81.0 

115 

June  10 

3>  80 

19.0 

4 

79 

85.  0 

175 

June  16 

3.50 

14.0 

5 

84 

90.  0 

115 

June  19 

3. 50 

16.0 

5 

86 

91.0 

115 

July  5  

3;  60 

15.0 

4 

81 

90.0 

135 

July  8 . . . 

8.  50 

20.0 

2 

83 

85.0 

115 

July  1 1 

3.40 

14.0 

3 

86 

86.0 

95 

July  16.. 

8. 10 

10.0 

2 

89 

94.0 

55 

Aug.  4  

8. 60 

13.0 

2 

81 

86.0 

135 

Aug.  6  

3.40 

11.0 

3 

82 

89.0 

95 

Aug.  11  ... 

3. 60 

14. 0 

12 

74 

81.0 

135 

Aug.  13  :  ... 

3. 60 

17.0 

2 

74 

81.0 

135 

Aug.  19  . 

3.20 

10.0 

3 

84 

90.0 

65 

Aug.  21  ... 

3.10 

•7.0 

2 

84 

86.0 

55 

oept.  i    -   

o  on 

19  A 

A 

JO.  ' ' 

3^ 

oO 

Sept.  2  _ . . 

2.80 

12.0 

5 

93 

90.  0 

30 

Sept.  5  - . 

2.90 

8.0 

3 

89 

97.0 

35 

Sept.  9  

3.00 

9.0 

3 

85 

89.0 

40 

Sept.  12 

3.05 

12.0 

3 

73 

85.0 

45 

Sept.  15  . 

3.  20 

12.0 

2 

1 1 

87.0 

65 

1901. 


Oct.  29 . 
Nov.  13. 
Nov.  23. 
Dec.  28. 


1902. 


Jan.  1  I 
Feb.  14. 
Mar.  18. 
May:: 
June  22 
June  23 
June  25 


HOUSATONIC  RIVER. 


4.  05 

4.83 
4.10 
5.16 

5.  00 
a  8. 30 

7. 63 
(>.  10 
4.70 
4.  50 
4.30 


19.0 
25.  0 
21.0 
14.0 

13.0 
20.0 
21.0 
20. 0 
24.  0 
18.0 
14.0 
o  Baekwatei 


103 
102 
100 
91 

89 
96 
53 
78 
89 
92 
1)8 


103.0 
106.0 
105. 0 
97.  0 

92.0  ! 
103.0 
60.0 
86.0 
92.0 
94.0 
95.0 


935 
1,860 

980 
2,420 

2,146 
8. 000 
8,277 
4.  159 
1.530 
1,177 
1.070 


PRBSSEY.  i 


QUALIT  V 


>F   RtVEE  WATER. 


85 


Turbidity,  <■<>/<>)•.  alkalinity,  <ni<l  hardness  of  streams — Continued. 


HOUSATONIC  KIVKK    ( '<>nt  inu.-d. 


Date. 

Gage 
height. 

Color. 

Turbid- 
ity. 

Alkalin- 
ity. 

Hard- 
ness. 

Discharge  in 
second-feet. 

1902. 

June  26  

4.  30 

15.0 

2 

94 

95.0 

1 . 070 

July  2 

4. 60 

18.0 

:! 

90 

!ll>.  1) 

1 . 400 

July  4.   

4.70 

20.0 

6 

91 

93.0 

1 , 530 

July  6   

4.50 

16.0 

2 

93 

93.0 

1. 177 

Julv  8  

5. 00 

22.0 

o 

91 

94.  0 

2. 145 

3. 90 

14.0 

5 

85 

101.0 

750 

July  18    

3. 90 

18.0 

i 

95 

98.0 

750 

Julv  22..   

6.70 

34.  0 

22 

63 

75. 0 

July  25  

5.60 

30.0 

12 

73 

82.0 

3, 050 

Julv  20.  _ 

4.90 

26.0 

88 

91.0 

1,800 

Aug.  1  

4.80 

35.  0 

1 

88 

94.0 

1 , 650 

Aug.  5 

4.20 

14.0 

4 

102 

109.0 

983 

Aug.  8    

4.  50 

14.0 

0 

102 

107.0 

1. 177 

Aug.  12  _. 

5.20 

32.0 

5 

73 

83.0 

2,300 

Aug.  15 

4.50 

31.0 

3 

85 

86.0 

1.177 

Aug.  19  

3.70 

11.0 

3 

96 

106.0 

Aug.  22  _  _ 

3.90 

11.0 

2 

96 

99.  0 

750 

Aug.  26 

3.  90 

11. 0 

4 

103 

107.0 

750 

Aug.  29  _ 

3.90 

10.0 

3 

96 

104.0 

750 

Sept.  2  J  

3.60 

10.0 

2 

98 

113.0 

640 

Sept.  5    

3.60 

9.0 

1 

104 

110.0 

640 

Sept.  9  _ .. . 

3.40 

10.0 

1 

105 

109.0 

490 

Sept.  12  

3.90 

13.0 

2 

97 

104.0 

750 

Though  the  number  of  observations  is  not  sufficient  to  give  accurate 
curves,  the  results  as  shown  in  the  tables  have  been  plotted  in  Pis.  I X, 
XI,  XII,  mikI  XIII"  and  tental  ive  curves  drawn  showing  the  relation  of 
these  qualities  to  the  discharge  of  the  st  ream.  In  thecurves  represent- 
ing alkalinity  and  hardness  the  relation  seems  to  be  well  marked.  The 
diagrams  show  the  relal  ive  hardness  of  the  various  st  reams,  also  rat  io 
of  decrease  in  hardness  as  the  discharge  increases.  The  regularity  of 
the  points  enables  one  to  prophesy  with  fair  precision  the  alkalinity  or 
hardness  that  might  be  expected  at  intermediate  discharges.  The 
turbidity  and  color  are,  as  might  be  expected,  far  more  irregular. 
It  would  not  be  expected  that  during  a  rapidly  rising  flood  we  should 
find  the  same  turbidity  as  at  the  time  of  general  high  water.  The 

«  Since  the  diagrams  were  plotted  many  more  observations  have  been  obtained  and  arc  included 
in  these  tables.  The  diagrams  have  not  been  changed,  as  they  are  only  intended  to  be  sag- 
gestive. 


80 


FLOW  OF  RIVERS  NEAR  NEW   YORK  CITY. 


[no.  76. 


effect,  too',  of  a  local  shower  on  one  tributary  may  affect  the  quality 
of  the  water  much  ^nore  than  the  same  increase  of  water  from  another 
tributary,  so  that  in  an  exhaustive  study  of  a  large  river  the  effect  of 
floods  on  each  tributary  is  important,  and  should  be  studied  rather 
than  the  river  as  a  Avhole.  Most  of  the  tributaries  of  the  streams 
under  consideration  are  short,  and  storms  would  usually  cover  a  large 
part  of  the  drainage  basin. 

It  is  not  considered  that  results  have  been  obtained  that  are  final 
upon  these  points,  so  that  their  publication  is  in  the  nature  of  a  prog- 
ress report.  Measurements  are  being  continued,  and  it  is  hoped  that 
better  curves  can  be  constructed  later.    The  curves  representing  tur- 


Fig.  8. — New  folding  turbidity  stick. 


bidity  and  color  are  merely  suggestions.  It  was  not  intended  that  the 
color  curves  of  the  Catskill  and  Tenmile  should  turn  so  far  to  the  left 
at  the  upper  part. 

GAGE  HEIGHTS   VXD  DISCHARGE  MEASUREMENTS. 

In  the  following  tables  arc  given  the  mean  daily  gage  heights  during 
the  years  L901  and  1902  at  the  stations  established  upon  the  Catskill, 
Esppus,  Rondout,  and  Fishkill  creeks,  and  Wallkill,  Tenmile,  and 
Housatonic  rivers. 

Following  these  tables  are  records  of  current-meter  discharge  meas- 
urements on  these  streams.  These  observations  and  measurements 
are  being  continued. 


pressey.]  GAGE  HEIGHTS.  87 

Mean  daily  gage  height  of  Catskill  Creek  at  Sou  fit  (  fairo,  N.  Y.,for  1901. 


July 


2.75 
2.  i) 

a  3 

3.6 

3.63 

3.35 

3.07 

3.53 

3.45 

3.23 

3. 0 

2.85 


Aug.  Sept 


2.55 

2.6 

2.55 

2.4 

2.4 

2.5 

3.35 

3.05 

2. 87 

2.8 

2. 77 

2.65 

2.55 

2.5 

2.5 

2.5 


3.0 

3.22 

3.27 

3.05 

2.92 

2.87 

2.9 

2.87 

2.82 

2.8 

2.75 

2. 77 

2.72 

2.7 

2. 75 


Oct. 


2.75 

2.7 

2.7 

2.67 

2.67 

2.62 

2.65 

2.6 

2.65 

2.6 

2.6 

2.65 

2.8 

3.1 

3.15 


Nov. 


2.7 

2.7 

2.65 

2.67 

2.67 

2.65 

2.7 

2.7 

2.65 

2.65 

2.65 

2.67 

2.8 

3.02 

2.85 

2.82 


Dec, 


2. 65 
2.65 
2.65 
8.3 
3.3 
3.32 
3. 32 
3.3 
3.35 
5.35 
4.62 
4.45 
3.95 
6. 95 
12.8 
5.6 


Day. 


July. 

3. 85 

3.78 

4.36 

3. 58 

3.  17 

2.67 

2.  95 

3.0 

3.02 

2.82 

2.7 

2.7 

2.72 

2.65 

2.6 


Aug. 

2.4 
2. 52 
2. 62 
2. 07 
2.  75 
3.05 
3.22 
3. 45 
3.55 
3.2 
2. 95 
2.8 
2.7 
2.65 


Sept. 

2.82 

2.97 

2.97 

2.82 

2.8 

2.8 

2.77 

2.72 

2. 67 

2. 65 

2. 65 

2.7 

2.8 

2.82 


Oct. 

3.02 

2.97 

2.9 

2.85 

2.82 

2.8 

2.8 

2.8 

2.8 

2.8 

2. 75 

2.  75 

2.  75 

2.7 

2.7 


Mean  daily  gage  height  of  Catskill  Creek  at  South  Cairo,  N.  Y.,  for  1902 


Day. 

Jan. 

Feb. 

Mar. 

Apr. 

May. 

June. 

July. 

Aug. 

Sept. 

Oct. 

Nov. 

Dec. 

1  

4.30 

11.70 

9.68 

5.35 

4.10 

2. 95 

3.48 
3.28 

4.50 

2.90 
2.83 

6. 18 

4.30 

3.60 

2.—  --. 

5.05 

5.88 

3.95 

2.88 
2.80 

5.58 

5.63 

4.15 

3.63 

3  - 

5.20 

6.70 

4.95 

3.93 

3. 13 

4.38 

2. 75 

5.20 

4.05 

3.80 

4   

4.45 

6.80 

4.88 

3.88 
3.83 

2.83 
2.88 

3. 10 

4.13 

2.73 

4.80 

3.95 

4. 18 

4. 40 

4. 40 

6. 35 

4.90 

3.08 

3.&5 

2.73 

4.60 

3.90 

4.00 

6.  

4.20 

4.40 

5. 40 

4. 65 

3.78 

2.88 

4. 45 

4.45 

2.70 

4.53 

3.83 

4.  00 

4.05 

4.30 

4.10 

4.40 

3. 73 

2.85 

4.20 

4.20 

2.73 

4.40 

3.77 

3.93 

8  L 

4.80 

4.25 

4.10 

4.60 

3.70 

2.90 

3.48 

3.93 

2.78 

4.23 

3. 73 

3.80 

9..  

3. 70 

4.20 

4.30 

11.65 

8.60 

2.80 

3.80 

3.80 

2.90 

4.05 

3.65 

3.70 

10  

3.55 

4.25 

5. 20 

8.25 

3.50 

2.75 

3.65 

3.65 

3.68 

3.90 

3.55 

4.05 

11   

3. 40 

4.40 

5. 75 

6.98 

3. 40 

2.70 

3. 60 

3.55 

3.55 

3.  as 

3.50 

4.40 

12  

3.30 

4.50 

9.10 

6. 48 

3:  30 

2.65 

3.55 

3.55 

3.28 

5.08 

3.55 

4.13 

13...  — 

3.30 

4.70 

9. 20 

5.50 

3.28 

2.78 

2.95 

3. 45 

3.40 

4.60 

3.63 

4.00 

14  -  

3.30 

4.95 

7.50 

4.  95 

3.23 

2. 75 

2.80 

3. 15 

3.53 

4.25 

3. 53 

4. 00 

15   

3.20 

3.10 

5. 45 

4.78 

3.20 

2.70 

2. 80 

3. 20 

3.35 

4. 15 

3.50 

3.  ft5 

16...-  

3.30 

3.20 

7.40 

4.58 

3.05 

2.75 

2.75 

3. 15 

3. 18 

4.25 

3. 40 

4.53 

17  ---- 

3.20 

3.40 

9.43 

4. 35 

3. 00 

2.90 

2.70 

3.05 

3.05 

3.93 

3.40 

6.35 

18  

3.00 

3. 50 

6.85 

4.25 

2. 95 

2.88 

2.65 

2.93 

2. 95 

3.83 

3.33 

5.43 

19 :  

2. 90 

3.60 

4. 15 

4.20 

2.90 

2.78 

2. 70 

3.05 

2.98 

3.80 

3.30 

5.00 

20  

2.90 

3.80 

4. 50 

4.20 

2.95 

2.85 

4.40 

3.10 

3.25 

3.83 

3.28 

4.80 

21  

3. 10 

3.80 

4.00 

4. 13 

2.95 

2.80 

7.25 

3. 03 

3.48 

3.  S3 

3. 30 

6.65 

22  

9. 85 

3.80 

4..% 

4.  10 

2.83 

2.80 

6.50 

2.98 

3.58 

3. 73 

3.20 

8.48 

23  _.rT   

5.90 

3.50 

5.58 

4.03 

2. 78 

2.80 

6. 53 

2. 93 

3. 18 

3.60 

8.20 

6.70 

24  

4.  SO 

3. 20 

5.48 

3.95 

2.90 

2. 78 

6.18 

2. 83 

3.10 

3.63 

3. 15 

5.13 

25   

4.40 

3. 40 

5.05 

3. 90 

2. 95 

2.70 

7.08 

2. 75 

3.  25 

3.60 

3. 80 

4.&5 

26  

4.03 

3.50 

4.93 

3.80 

2.85 

2.68 

7.85 

2.70 

3. 58 

3.50 

3.30 

6.65 

27  

3.85 

4.83 

4.83 

3.83 

3.10 

2.65 

4.  ft") 

2.70 

4. 85 

3.55 

3. 85 

4.35 

28  

3.58 

9. 15 

5.03 

3. 73 

8.38 

2.60 

4.20 

2. 73 

"4.70 

5.90 

4. 13 

4.20 

29  

3.  70 

5. 73 

3.95 

3.25 

2.80 
3.88 

4.40 

2.85 
2.98 

9.95 

5.30 

3.80 

4.13 

30  

4. 25 

5. 93 

4.  10 

3. 13 

4.38 

7.20 

4.70 

3.63 

3.95 

31  

4.30 

5. 43 

3.00 

4.25 

3.08 

4. 45 

3.85 

a  12 o'clock  midnight,  16.1. 


88  FLOW  OF  RIVERS  NEAR  NEW   YORK  CITY.  tso.76. 

Mean  daily  gage  height  of  Esopus  Creek,  at  Kingston,  N.  V..  for  1901. 


Day. 


July. 


10... 

U... 

12... 

13... 

14. 

15... 

16— 


4.3 

4. 35 

4.3 

4.4 

4.4 

4.25 

4. 25 

4.3 

4.3 

4.2 

3.95 

4.2 


Aug. 


3.97 

3.95 

3. 9 

4.95 

3.95 

3.7 

3.95 

7.0 

5.  72 

5.17 

5.05 

4.87 

4.72 

4.6 

4.42 

4.42 


Sept. 


Oct.  Nov. 


6. 47 

6.3 

6.67 

6.27 

5.8 

5.57 

5.42 

5.02 

5. 17 

4.95 

5.02 

4.87 

4.9 

4.87 

4.72 

4.75 


4.  52 

4.62 

4.7 

4.52 

4.42 

4.3 

4.47 

4.57 

4.5 

4.52 

4.47 

4.4 

4.5 

4.52 

4.57 

4.65 


4.62 

4.52 

4.35 

4.37 

4.55 

4.47 

4.  57 

4.47 

4.32 

4.32 

4.45 

4.57 

4.6 

4. 45 

4.37 

4.43 


Dec. 

4.6 
4.52 
4.77 
5. 45 
4.  62 
4.67 
4.72 
4. 65 


5.6 
11.5 
9. 72 
7.35 
8.12 
21.37 
15.2 


Day. 


July. 


17   4.05 

18  |  4.05 

19..  '.J  4.6 

20  I  4  15 

21   4.1 

22   3.9. 

23  j  4.C5 

24  ....  !  4.0 

25...   3.9 

26    3.S7 

27    3.92 

•28   3.85 

29   3.72 

30   4.2 

31   4.25 


4.37 

4.54 

4.5 

4.77 

5. 95 

6.62 

5.92 

7.35 

7.67 

6.52 

6.02 

5.87 

5.  72 

5. 45 

5.22 


Sept. 

Oct. 

Nov. 

Dec. 

5.0 

4.47 

4.3 

10.55 

5. 27 

4.42 

4.37 

9.05 

5.07 

4.6 

4. 52 

8.1 

5. 35 

4.77 

4.5 

8.0 

5.17 

4.77 

4.47 

7.75 

4.77 

4.67 

4. 52 

7.2 

4.92 

4.67 

4.45 

6.85 

4.77 

4.62 

4.52 

6.7 

4.5 

4.62 

4.62 

6.5 

4.37 

4.52 

4.6 

6.35 

4.5 

4.42 

4.57 

6.25 

4.72 

4.45 

4.77 

6.0 

4. 45 

4. 57 

5.45 

7.55 

4.42 

4.47 

4.52 

11.65 

4.6 

9.45 

Mean  daily  gage  height  of  Esopus  Creek  at  Kingston,  N.  Y.,  for  1902. 


Day. 

Jan. 

Feb. 

Mar. 

Apr. 

May. 

June. 

July. 

Aug. 

Sept, 

Oct, 

Nov. 

Dec. 

1 

8.20 

7.25 

12.10 

9.35 

8.95 

4.85 

6.38 

7.09 

4.45 

13.38 

7.28 

5.90 

2   ...... 

10. 35 

7.45 

16.82 

8.  ti'.t 

8.18 

4.83 

6.19 

7.95 

4. 48 

11.68 

6.75 

5.70 

3  

it.  95 

9. 35 

15.  75 

8.05 

7. 78 

4. 76 

6.  (X) 

7. 10 

4. 43 

10. 10 

5. 83 

6. 19 

4   ----- 

8.40 

7.72 

11.07 

7.64 

7.70 

4.83 

6.40 

6.90 

4.33 

9.50 

6.53 

6.43 

5  

7.65 

7.52 

9.45 

7.33 

7.43 

4.70 

5.09 

6.53 

4.38 

8.60 

6.55 

6.33 

6  

7.30 

7.16 

8.95 

7.03 

7.11 

4.73 

6.19 

7.08 

4.33 

9.64 

6.25 

6. 18 

7  

6.95 

6.70 

7.90 

7.18 

6.98 

4.55 

6.16 

6.90 

4.38 

8.68 

6.47 

6.35 

8  

6. 65 

6.47 

7.68 

7.28 

6.74 

4.63 

6.03 

3.43 

4.38 

8.18 

6.35 

6.60 

9   

0.  50 

0.14 

8. 85 

13. 10 

6.55 

4.63 

5.80 

6.18 

4.38 

7.85 

6. 13 

6.45 

10...  

6.  40 

6.25 

9.20 

13.86 

6.  40 

4.(58 

5.58 

5.88 

7.68 

7.40 

6.00 

6.00 

11   

6.35 

5.94 

0.05 

11.60 

6.23 

4.58 

5.50 

5.83 

6.00 

7.15 

7.85 

6.35 

12  

5.88 

5. 88 

9. 80 

10.22 

6.10 

4.  45 

5.34 

6.25 

5.  49 

9. 10 

7. 95 

6.55 

13  

0.00 

5.77 

11.85 

9.41 

5. 96 

4.53 

5. 15 

5. 73 

5. 53 

8.47 

5.85 

6.35 

14  si  

5. 93 

5.60 

11.82 

8.78 

5.88 

4.58 

5.05 

5.58 

6.18 

8.00 

5.78 

6.40 

15  

5.60 

5.58 

0. 98 

8. 25 

5. 70 

4.40 

4.98 

5.38 

5.85 

7.60 

5. 73 

6.43 

16  

5.58 

5.53 

9. 33 

7.90 

5. 70 

4.46 

4.99 

5. 30 

5.53 

7.33 

5.63 

6.65 

17   

5. 59 

5. 63 

«18.28 

7.58 

5.50 

4.78 

4.89 

5.08 

5. 30 

7.15 

5.60 

16.20 

18...  

5.30 

5.3;) 

13.10 

7.35 

5.33 

4.94 

4.80 

5. 10 

5. 13 

6.95 

5.(50 

12.86 

19  

5. 50 

5. 45 

10.13 

7. 10 

5.38 

4.63 

4.78 

4.98 

5.08 

6.75 

5.54 

11.00 

20  

5.37 

5.30 

0.20 

0. 93 

5. 30 

4.60 

6.88 

4.98 

5. 80 

6.73 

5.  46 

9.95 

21  

4. 95 

5. 35 

8.62 

6.80 

5. 28 

4.81 

10.00 

4.88 

6.88 

6.47 

5.  45 

8.55 

22  

12.  73 

5. 36 

8.25 

6.78 

5. 13 

5.55 

9.50 

4.85 

6.28 

(5. 30 

5.  38 

15.60 

23  

10.88 

5.30 

8. 20 

6. 93 

5.03 

5.13 

9.28 

4.78 

5. 88 

6.20 

5.36 

12.80 

24  

8.88 

5. 36 

7.87 

6.88 

6.00 

4. 93 

8.138 

4.65 

5.68 

6.13 

5. 86 

10.40 

25  

8.00 

5. 39 

7.63 

6.58 

4.88 

4.81 

8.58 

4.70 

5.68 

6.30 

6.90 

9. 35 

26  

7.53 

6. 45 

7.43 

6. 36 

5. 20 

4. 93 

8.68 

4.65 

7.00 

5.87 

5.30 

8.70 

27  

8.63 

0.30 

7.28 

6. 35 

5.20 

5. 15 

8.01 

4.55 

10.86 

5. 78 

6.00 

8.28 

28  

8.08 

9.37 

7.17 

6.  20 

5.  .58 

4.84 

7. 75 

4.65 

9. 48 

7.83 

0.  60 

8. 75 

29  

7. 72 

11.65 

5.08 

5. 25 

4.81 

7.  10 

4.70 

?>22. 43 

8.  35 

(5.  10 

9. 10 

30  

7.82 

12.55 

0.81 

5.03 

7.10 

7.68 

4.60 

17.85 

7. 75 

5.88 

8. 07 

31  

7.48 

10.  45 

5.03 

7.  as 

4.63 

7.. 50 

8.05 

"  Highest  water  at  1,30  p.  m., 25.25.  &  Highest  water  at  1.80  p.  m.,  18.30. 


PRESSEY.  1 


(iACK  HEIGHTS 


89 


Mean  daili/  gage  height  of  Rondont  ('reek  of  R 


lolc  N.  )  '..  for  1901. 


Day.       July.  Aug.  Sept. 


.  6.5 
.  (5.4 
.  0.25 
.  6.2 
J  6.25 
.  6.3 
J  6.33 
.  6.3 
J  6.38 


7.57 
5.  S 
6.8 
6.25 

1.6.17 
6. 35 
9.  75 
7.35 

i  6.92 
6. 62 
7.17 
7.42 
6.87 
(5. 55 

I  6.50 
(5.52 


7.88 
7. 96 
7.8 
7.(51 
7.42 
6. 97 
(5.  87 
6.77 
6. 67 
6.6 


6. 72 
6.57 
6.5 
6.62 


Oct. 


6. 95 

6.8 

6.7 

6.62 

6.55 

6.55 

6.52 

6.  4."> 

6.42 

6. 42 

6.5 

7.25 

7.72 

7.37 


Nov.  Dfc 


(i.  5 
(5. 5 
6.5 
ti.  45 
(i.4 
6.4 
(i.4 
(i.4 
6.4 
(i.4 
6.37 
6.45 
6.95 
6.8 
6.62 
6.6  Il0.6 


6.55 
6.4 
6.5 
6.&5 
(i.  87 
6.85 
6.92 
7.0 
7.2 
9.2 
9.25 
8.22 
7.  75 
8.97 


Day. 

July. 

Aug. 

Sept. 

( )<-t. 

Nov. 

Dec. 


17  

6.8 

(i.  5 

(i.  67 

7.1 

6  56 

8.95 

18  

(i.  86 

(5.  75 

7.05 

7.0 

c.  55 

8.04 

19   

(i.  55 

7.0 

0.  85 

6.9 

(i.  56 

7. 77 

20  

6.-18 

6.85 

6.  66 

6.8 

6. 5 

7.55 

21  

(i.  47 

8.  75 

<;.  55 

(i.  72 

6.4 

7.56 

22  

(5.  87 

8. 15 

6. 52 

6.7 

(i.  85 

7. 57 

23  

6.4 

7. 5 

6.47 

6.  7 

6.4 

7.95 

24  

6.35 

9.0 

<;.  42 

6.6 

6. 5 

7.  75 

25  ... 

6. 35 

9.4 

6.4 

6.6 

7.6 

7.22 

26  

6.3 

8.1 

6. 35 

6.6 

7.25 

7.12 

27  

6. 47 

7.47 

(i.  32 

6.  6 

(5. 97 

7.0 

28  

(5.42 

7. 15 

6.3 

(i.l.5 

6. 87 

7.35 

(i.  95 

7. 05 

C.5 

6.8 

9.1 

30  

6.67 

7.42 

7.41 

6.5 

6.8 

12. 12 

31  

6.  72 

6.  72 

6. 5 

10.0 

Mean  daily  gage  height  of  Rondont  Creek  at  Rosendqle,  A'.  Y..  for  1902. 


Day. 

Jan. 

Feb. 

Mar. 

Apr. 

May. 

June. 

July. 

Aug. 

Sept. 

Oct. 

Nov. 

Dec. 

1 

8.73 

8.98 

17.20 

8. 18 

8. 25 

6.58 

• 

7.08 

7.70 

6.25 

10.03 

7.25 

6.73 

2  

7.90 

8.95 

14.23 

7.85 

7.70 

6.48 

6. 90 

8. 35 

6.20 

^9.28 

7.05 

6.70 

7. 90 

9. 75 

12. 53 

7.58 

7.  70 

6. 55 

6.98 

7.60 

ti.  L3 

8.43 

7.03 

6.90 

4  

7.£0 

9.35 

9.75 

7.58 

7.  75 

(5. 63 

7.70 

7.28 

6. 15 

7.93 

7.00 

7.20 

5   

7.90 

9.70 

8.70 

7.35 

7. 50 

6.48 

7.23 

7.08 

(5. 10 

7.80 

6.90 

6.88 

6   

7.83 

9.25 

8.05 

7.25 

7.33 

6.40 

7.13 

7.25 

6. 18 

8.78 

6. 87 

6.80 

jL58 

9.  CO 

7.95 

7.60 

7.28 

6.48 

7.00 

7.33 

6.20 

8. 00 

6.95 

6. 95 

8  

7#2S 

8.83 

7.fw 

8. 10 

7.15 

6.  45 

6.88 

7.03 

6.20 

7.65 

6.85 

6.98 

9..  

7. 13 

8.58 

9.40 

12.28 

7. 03 

6.48 

6.85 

6. 93 

0.23 

7.38 

6.80 

6.88 

10  

7.08 

8.05 

9.70 

11.40 

6.  93 

6.:* 

6.65 

6.83 

7.00 

7.18 

6.78 

7.10 

11.   

7.10 

8.18 

9.30 

9.  75 

6.8* 

6. 30 

6.58 

6.80 

6.58 

6.95 

6. 73 

7.08 

12  

7.85 

8.05 

9.70 

9. 15 

6. 8S 

6.35 

6. 63 

6.£0 

(5.  40 

9.  75 

6.73 

7.00 

6.95 

7.98 

11.05 

8.(53 

6.83 

6.35 

6.5J 

(i.  80 

(5. 45 

8.  (55 

(5. 73 

6.95 

14  

(5.  73 

7.88 

10. 15 

8. 15 

6. 68 

6.38 

(i.  45 

(5.  70 

6.68 

8. 00 

6. 70 

7. 15 

6.83 

7. 80 

9. 15 

7.  a") 

6.(53 

6. 3') 

6. 85 

(5. 55 

6.  48 

7. 57 

ti.  70 

7.  .50 

16  

6.90 

7. 65 

8.80 

7.(55 

6.  70 

(5.  35 

(5.  40 

6. 58 

6. 36 

7. 35 

(i.  70 

8.35 

6.78 

7. 53 

13. 10 

7.50 

6.  (50 

6.50 

6. 33 

(5.  .50 

(i.  25 

7.23 

ti.  65 

12.95 

18  

6.  70 

7.(50 

9.95 

7.38 

6.  63 
6.  (50 

(i.  45 

6.30 

(i.  4_> 

6.20 

7.07 

(i.  65 

10.00 

19  

6.7S 

7.35 

8.65 

7.25 

(5.80 

6.33 

0.4:) 

0. 18 

7.07 

6.6S 

8.80 

20  

6.70 

7.43 

8.25 

7.18 

6.00 

(i.  43 

7.63 

(5.  4!) 

0.25 

7.00 

0. 65 

8.30 

21...   

(i.  73 

7.43 

8.08 

7.10 

6. 68 

fi.  43 

8. 93 

ti.  38 

(5.  .50 

0.  !I5 

0.  ti") 

8.35 

22  

14.68 

7.40 

8.00 

7.05 

6.50 

7.10 

9.  18 

0.  48 

6.  40 

K90 

ti.  65 

13.  45 

23   

9  83 

7.43 

7.88 

7.  00 

6.  48 

(i.  70 

8.38 

6.40 

6.  23 

6.80 

ti.  60 

10.  .58 

24  

8.35 

7.4* 

7.80 

6.90 

6.  45 

6. 50 

09.94 

0.40 

(i.  25 

0.80 

6.60 

9.55 

25  

7.65 

7.63 

(5.8S 

6.  40 

0.40 

10.34 

6.  35 

0.  45 

6.80 

6.55 

8.50 

26  

7. 68 

8.23 

7.  45 

6.98 

6.80 

(i.  43 

S.  5)5 

6.:* 

9.40 

(i.  73 

6.70 

8.  10 

8.95 

10.68 

7. 88 

6.95 

6.88 

6.50 

8.23 

6.28 

9.  75 

6.63 

ti.  75 

8. 87 

£8  

7.75 

12.10 

7.33 

6.83 

7.20 

6.43 

7.80 

6.  £5 

8.68 

9. 38 

6.90 

7.45 

29  

8.00 

9. 86 

6.  78 

6. 86 

6. 45 

7.38 

6. 83 

'<1 4.0*.i 

8.60 

(i.  88 

7. 27 

30  

8. 18 

9.  53 

9.  SB 

6.60 

7.70 

7.80 

6.30 

L0.78 

7.83 

6.80 

7.20 

31.  

8.60 

8.63 

(i.  63 

7.33 

6,80 

7.  45 

7.20 

"Highest  water,  12.65,  at  7  p.  m. 


''Highest  water,  16.6,  -it  8  p.  m. 


90 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY. 


[no.  76. 


Estimated' diversion  from  Rondout  Creek  to  Delaware  and  Hudson  ( 'anal,  Rosen- 
dale,  N.  Y,  1902,  in  second-feet. 


Day. 

Jan. 

Feb. 

Mar. 

Apr. 

15.5 
17.7 
21.5 
22.0 

May. 

Jnne. 

Ji*ly. 

Aug. 

Sept. 

Oct. 

Nov. 

Dec. 

.^t^i  

22.6 
15.0 
24. 6l 

24.2 
23.8 
23.1 

26. 0 
25.6 

22. 6 
22.4 
26.1 
25. 8 

22.2 
23.1 
22.4 
21.9 
22.8 
22. 1 

22. 5 

2  

25.2 
20.8 
11.6 

9A  3 

25.3 
22.5 
24.3 
25.3 
25.8 

3   

21.0 
23.5 
21  5 
23. 3 

24.8 

4  

23.8 
24.5 
22.5 
24.5 
23.8 
24.0 

24.0 
24.5 
24.6 
26.0 
24.8 
24.5 

17.9 

27.6 
23.1 
24.8 

91  1 

6  

19.5  1  

21.8  1  23.1 
  22.7 

23. 8  24. 3 

35.9  ,  25.3 

7 

20.4 

8  

20.2 
18.4 
14.3 
20.7 
19.2 

24.3 
24.6 
24.5 

25.0 
23.5 
24.3 
24.3 
25.1 
22.2 

9..  ft  

10  

11  

24.9 
33. 8 
27. 5 
23.6 

26.1 
21.8 

12...  b  

24.3 
24.1 
25. 0 
24.1 
24.5 
22.8 

13  L  

2l).  4 
20.6 
20.  5 
19. 5 
19. 5 
19.7 

14   

25.4 
25.7 
24.2 
25.1 
26.1 
25.6 

25. 3 
25.3 
24.2 
26.0 
25.1 
22.7 

26.5 
25.6 
25.8 
23.3 
24.8 
22.0 

16  

22.3 
22.6 
24.3 
23.8 
23.9 
24.4 

17  

18  

25.5 
24.3 
23.8 
25.1 
25.6 
24.3 

19..  

24.3 
24.6 
23.1 
23.6 
:.-).  6 
24.3 

20  

21.3 
23.5 
21.0 
21.2 
23.0 
20.4 

21  

25.9 
26.7 
24.1 
23.3 
23.4 
22.8 

23.8 
25.6 
22.8 
20.6 
19.0 
22.8 

22..  

24.3 
23.8 
24.0 
25.1 
22.8 
22.6 

23  

15.8 
11.4 
12.3 
15.3 
30.9 
16.4 

22.1 
20.1 
22.6 
22.8 
19.8 
22.6 

24..  

25  

22.8 
22.2 
25.1 
22.5 
25.8 
23.0 

26  . 

21.1 
28.0 
26.5 
26.3 
20.7 
24.1 

27  

22.8 
23.8 
24.3 
23.0 
25.0 

28  

27.1 
25.2 
25.8 

25. 6 
21.6 
23.6 
26.4 

29  

20.3 
22.1 

30...   

26.7 

31  



21.8 

Mean 

22.5 

24.0 

23.7  1-23.8 

24.3 

24.0 

22.2 



Mean  daily  gage  1  id  (pit  of  Wallkill  River  at  New  Paltz,  N.  Y.,  for  1901. 


Day.  July 


7.27 
7.23 
(i.  93 
6. 65 
6. 53 
7.33 
7.»>0 
7. 15 
6.  S3 
6.55 


Aug. 


6. 10 
5.90 
5. 97 
6.00 
6.  45 
6.  45 
12.05 
11.25 
9.30 
9.  15 
9.  10 
8.05 
7.70 
7.15 
7.40 
7. 10 


Sept. 


Oct. 


9.20 
9.85 
9.75 
9.35 
8.55 
8. 35 
8.05 
7.70 
7.47 
7.  45 
7.25 
7.05 
7.15 
6. 95 


7.45 
7.25 
7. 15 
7.00 
6.  95 
6.85 
6.65 
6.  47 
6.35 
6.80 
6. 30 
6.20 
6.20 
6.35 
7.50 
7.85 


Nov.  Dec. 


6. 00 
6.00 
6.00 
6.00 
6.05 
6. 10 
6.00 
5.95 
5.85 
5. 75 
5.65 
5.  95 
6.40 
7.00 
6.90 
6.55 


6.25 
6. 05 
6.  (X) 
6. 20 
0. 35 
6.65 
6.60 
7. 30 
10.00 
12.30 
11.70 
10.30 
10.05 
10.60 
13. 30 
12.85 


Day. 


July 


6. 37 
7.15 
7.98 
7.20 
6.50 

6.a5 

6.25 
6.05 
6.00 
6.00 
5.85 
5.85 
5. 86 
5.80 
:».«•:, 


Aug. 


6.75 
9. 25 
11. 15 
10.15 
10. 25 
10.25 
10. 15 
9.70 
14.30 
12.00 
11.25 
10.  BO 
9.90 
9. 15 


Sept. 


7.06 
7.62 
7.  65 
7.  45 
7.30 
7.10 
6.  95 

6.  m 

6. 65 
6.50 
6  85 
c.  86 
6.65 
7. 25 


Oct.  I  Nov.  Deo. 


7.50 
7.27 
7. 15 
6.95 
6.  70 
6.45 
6.32 
6.30 
6.20 
6. 12 
6.10 
6  10 
6. 10 
6.10 
(i.50 


6.  25 
6.05 
6.15 
6.35 
7. 30 
8. 10 
8.65 
8.35 
8. 10 
7.45 
6.96 
ti.  86 
6.65 
6. 45 


13. 10 
13. 66 
13. 75 
12.95 
11.70 
10.  70 
10.45 
10. 15 
9. 55 
9.00 
9.  25 
9.70 
LI.  80 
19.35 
19. 20 


pressey.]  GAGE  HEIGHTS.  91 


Mean  daily  gage  height  of  WaUkill  Hirer  at  New  Paltz,  N.  F.,  for  1902. 


Day. 

Jan. 

Feb. 

Mar. 

Apr. 

May. 



June. 

July. 

Aug. 

Sept. 

Oet. 

Nov. 

Dee. 



1  

15.15 

8. 75 

23.53 

9.  :*-> 

10.25 

7.50 

7.25 

9.50 

6.  10 

10.25 

8. 65 

6.80 

2  

13.25 

8. 75 

23.80 

8.95 

8.95 

7.25 

7. 15 

9. 10 

6.05 

10.85 

8.a5 

6.70 

3  

12.95 

10.65 

«24.65 

8. 65 

9. 15 

7.05 

7.50 

8. 75 

6.00 

10.  15 

8. 15 

7.50 

4  

12.10 

9.70 

22.75 

8.20 

8.85 

6. 90 

7.58 

8.60 

5.88 

9.66 

7.95 

7. 95 

5----  

.10.45 

9. 75 

20.25 

8.00 

8.35 

6. 55 

7.08 

8.30 

5. 78 

9.60 

7.65 

8.10 

6  

10.70 

8.90 

15.20 

9.  70 

7.95 

6.  35 

6.  78 

7. 95 

5. 70 

W.  10 

7.50 

8.55 

10.20 

8.15 

13.20 

7.70 

7.50 

6.30 

6. 53 
6. 35 

7.85 

5.60 

9.45 

7.50 

8.10 

8  

8.70 

7.85 

12.70 

8.40 

7.45 

6.25 

7.65 

5.50 

9.00 

7.65 

7.70 

9  

9. 15 

7.78 

14.90 

M3. 65 

7.35 

6.30 

6.23 

7.30 

5.50 

8.55 

7.15 

7.70 

10  

8.85 

7.70 

16.45 

13.50 

7.10 

6.50 

6. 10 

7.  ft") 

6.10 

8.40 

6.95 

7.65 

11  

8.75 

7.55 

15.90 

12.20 

6.80 

6.35 

6.00 

6.90 

6. 45 

8.25 

6. 75 

7.60 

12:  

8.20 

7.55 

16. 10 

11.65 

6.65 

6. 30 

6.00 

6.80 

6.30 

12.45 

6.70 

7.80 

13   

8.05 

7.40 

17.05 

10.65 

6.60 

6.20 

iS.90 

6.75 

6.  .35 

11.90 

6.60 

7.55 

14  

8.05 

7.a5 

16.50 

9.80 

6.55 

6. 15 

5. 78 

6.68 

6. 45 

10.50 

6.60 

7.50 

15  

8.00 

7.15 

15.00 

9.&5 

6.50 

6.10 

5. 70 

6.60 

6.25 

9.70 

6.60 

7.50 

16  

8,00 

7.10 

14.65 

8.65 

6. 45 

6.20 

5. 70 

6.53 

6. 15 

9.35 

6.50 

7.50 

17..  

7.70 

7.20 

15. 40 

8.20 

6. 35 

6.25 

5.73 

6. 43 

6.05 

9.00 

6.50 

12.20 

18   

7. 55 

7. 15 

13.75 

8.00 

6.30 

6.15 

5.58 

6.38 

5.95 

8.60 

6.50 

12.25 

19  

7.50 

7.08 

11.75 

7.85 

6.30 

6.13 

5.55 

7.28 

5.80 

8.60 

6. 50 

12.30 

20  

7.20 

7.00 

10.60 

7.60 

6. 30 

6.10 

6. 10 

6.20 

5.90 

8.15 

6.50 

12.30 

21  

7.20 

7.05 

10.30 

7. 45 

6.30 

6. 13 

7.78 

6. 15 

5.90 

7.95 

6.40 

12.95 

22- 

18.50 

7.05 

10.20 

7.35 

6.30 

6.33 

8. 65 

6.10 

5.90 

7.65 

6.40 

19.00 

23--  ----- . 

1165 

7.10 

9. 75 

7. 15 

6. 25 

6.40 

7.40 

6.05 

5.90 

7.47 

6.65 

19.65 

24  

7.25 

9.60 

7.10 

6.20 

6.35 

cll.00 

6. 10 

5.90 

7.37 

6.30 

17.20 

25  

13. 15 

7.30 

9.45 

6. 95 

6.20 

6.20 

dl4.00 

6.05 

6.15 

7.15 

6.30 

16.25 

26  

12.20 

7. 75 

9.00 

6.85 

6.45 

6.20 

9. 10 

6.00 

9.65 

6.95 

6.35 

15.30 

27  

12.85 

11.40 

8.50 

7.00 

8.30 

6.10 

8.50 

6.00 

12.00 

6.85 

7.35 

14.20 

28.  

12.65 

12.75 

8.20 

6. 75 

9.20 

6.03 

7.80 

5.95 

11.90 

11.65 

7.35 

14.20 

29  

11.15 

10.20 

6.65 

8.40 

6.13 

7. 45 

8.25 

13.45 

11.25 

7.10 

13.80 

30   9 

9.50 
9.25 

11.05 
9.90 

ell. 75 

8.30 
7.90 

7.00 

7. 45 
8.45 

6.95 
6.40 

10.35 

9.45 
8.95 

6. 95 

12.30 
11.75 

31  

a  Highest  water  24.80  at  p.m.  c  Highest  water  15.4  at  8  p.  m.  e  Highest  water  12.6  at  p.  m. 
i>  Highest  water  14. 6  at  p.  m.        ''Highest  water  16.6  at  9  p.  m. 


Mean  daily  gage  height  of  Fishkill  Creek  at  Glenham,  N.  Y.,for  1901. 


Day 


3.90 
3.90 
3. 80 
3. 78 
3.83 
3.80 
3.73 
:<.ro 
3.65 


Aug. 

Sept. 

Oct. 

Nov. 

Dec. 

3.95 

4.57 

4.05 

3.97 

3.90 

3.82 

4.60 

3.97 

3. 95 

3.98 

3.77 

4.47 

4.10 

3.95 

4.05 

3.  67 

4.42 

4.10 

3. 95 

4.08 

3. 65 

4.30 

4.00 

3. 90 

4. 10 

3.65 

4.  15 

3.92 

3.90 

4.25 

4.70 

4.  17 

3.90 

3. 92 

4.28 

5.55 

4.10 

3. 87 

3. 95 

4. 18 

4.77 

4.07 

3.85 

3.90 

4.05 

4.35 

4.02 

3. 85 

3. 87 

4.73 

4.12 

4.05 

3.85 

3. 87 

5.33 

4.07 

4. 37 

3.80 

3.92 

4.83 

4.02 

4.32 

3.80 

4.32 

4.60 

3. 90 

4.  15 

4.30 

4.17 

4.68 

3. 90 

4.  10 

4.85 

4.  0=5 

6.78 

3. 82 

4.25 

4.82 

4.00 

7. 45 

Day. 


July.  Aug 


23  

24....  

25  

26  

27  



29  

30.-..  

31  


3.73 
4.23 
4.00 
3.90 
3.  77 
3.70 
3.65 
3.65 

3.  <;.-> 

3.62 
3. 60 
3. 45 
3.57 
4.35 
4. 15 


Sept, 


Oct. 


3.85 
5.07 
4.70 
4.40 
4.  45 
4. 95 
4.62 
4.70 
6.40 

6.55 

5.65 
5.20 
4.S5 
4.70 
4. 57 


4. 15 
4.22 
4.12 
4.02 
4.02 
4.00 
3.92 
3.90 
3.87 
3.85 
3.80 
3.87 
3. 96 
4.20 


4. 55 
4.40 
4.32 
4.22 
4.20 
4. 15 
4.12 
4.10 
4.05 
4.00 
4.00 
4.(10 
4.110 
4.  00 
8. 97 


92  FLOW   OF  RIVERS   NEAR  NP]W    YORK  CITY.  [no.  7(5. 


Mean  daily  gage  height  of  Fishkill  ('reel,-,  of  Glenham,  N.  )'..  for  inn'. 


Day. 

Jan. 

Feh. 

Mar. 

Apr. 

May. 

June. 

July. 

Aug. 

Sept. 

Oct. 

Nov. 

Dee. 

1 . 

6.05 

5.00 

13. 00 

4.90 

5.48 

3. 83 

 — 

3.  70 

3.80 

2.90 

4.25 

4.40 

3.70 

2           .  .'. 

5.  65 

4.75 

10.00 

4.78 

4. 93 

3. 70 

3.53 

3. 70 

2.80 

4.20 

4.33 

3. 73 

::   

5.50 

5.63 

8.78 

4.68 

4. 70 

3. 00 

3. 45 

3.60 

2. 95 

4.00 

4.20 

3.88 

4 

5. 90 

5.55 

6. 70 

4.00 

4.73 

3. 70 

3.85 

3.60 

2.73 

3.83 

4.15 

4.03 

5   . 

5. 18 

5.  .58 

5.80 

4.  53 

4.63 

3. 70 

3.60 

3.50 

2.90 

3.83 

4.05 

3.98 

6    

4.5)5 

5.28 

4. 95 

4.  45 

4.45 

3.55 

3. 70 

3. 43 

2.95 

4.20 

4.03 

3.70 

7  

4.80 

5. 25 

5.05 

4.53 

4.35 

3.50 

3. 70 

3. 48 

2.90 

4.20 

4.00 

3. 70 

8  -  -   

4.70 

5.00 

5. 15 

4.63 

4. 30 

3. 85 

3.55 

3. 40 

2. 95 

3.93 

4.00 

3.80 

9   .... 

4. 65 

5.13 

5. 90 

5.13 

4.20 

3.85 

3. 45 

3.40 

3.00 

3.85 

3.93 

3.98 

10.-  

4.6:5 

5. 05 

7. 75 

5.  65 

4. 10 

3.75 

3.:* 

3.30 

3. 33 

3. 78 

3. 90 

4.05 

11.   

4.  CO 

4. 75 

6. 95 

5.53 

3.90 

3. 60 

3.40 

3. 50 

3. 25 

3. 70 

3.88 

3. 85 

12  

4.5S 

4. 80 

6.50 

5. 28 

3.98 

3.50 

3. 30 

3.85 

3.08 

4. 95 

3.88 

3.90 

13   

4.75 

4.60 

6. 70 

5. 05 

3.95 

3. 40 

3. 23 

3.65 

3.  m 

5. 03 

3.88 

4.05 

14  

5. 0!) 

4.40 

6. 63 

4.90 

3. 90 

3.  43 

3.20 

3.48 

3. 23 

4.08 

3.88 

4.10 

15   ..... 

4.70 

4.  as 

5.98 

4.80 

3. 90 

3.50 

3. 13 

3.  40 

3. 20 

4.35 

3.80 

4.30 

16  

4. 35 

4.  25 

5. 65 

4.70 

3. 90 

3.50 

3. 13 

3.&5 

3. 15 

4.20 

3.83 

4.40 

4.28 

4.48 

6.73 

4.00 

3.  80 

3.95 

3.10 

3.28 

3. 15 

4.80 

3.80 

6.65 

18  

4.25 

4.38 

6. 45 

4.58 

3.  70 

3.  70 

3. 10 

3.20 

3.18 

4.00 

3.70 

7.55 

19.  

4.25 

4.33 

5. 70 

4.50 

3.75 

3.50 

3.08 

3.20 

3. 00 

4.00 

3.  70 

6.  .50 

20-....  . 

4.18 

4.35 

5. 20 

4.40 

3.80 

3.53 

3. 20 

3. 15 

3.05 

3.95 

3.68 

5.98 

21  .  

4.18 

4.38 

5.30 

4. 35 

3.83 

3.50 

4.15 

3. 10 

3. 03 

3. 90 

3.63 

5.50 

22  

5. 88 

4.85 

5. 23 

4.30 

3.68 

3. 75 

4.70 

3. 15 

3. 15 

3. 80 

3.60 

7.  75 

23   I: 

6.  55 

4.85 

5. 13 

4.23 

3.68 

3.60 

4.65 

3. 10 

3.08 

3.80 

3.60 

8.05 

24   ... 

5. 15 

4. 90 

5.00 

4. 15 

3.60 

3.50 

4.10 

3. 10 

3. 13 

3.70 

3.63 

7.00 

25 

4. 75 

4.  70 

4.85 

4.05 

3.60 

3.40 

4. 18 

3. 15 

2.95 

3. 75 

3.63 

5.95 

26  

4.6:5 

4.85 

4. 75 

4.05 

4.20 

3.50 

4.10 

3. 05 

3.48 

3. 73 

3.08 

5.60 

27  

5.00 

5. 88 

4.70 

4. 13 

4. 15 

3. 40 

4. 05 

3.00 

3. 60 

3. 70 

3. 95 

5.40 

28  

5. 00 

7.10 

4.55 

4.08 

4. 58 

3. 30 

3. 90 

3.00 

3.60 

4.65 

3.88 

5.05 

29  

4. 95 

4. 85 

4.00 

4.23 

3. 35 

3.80 

2. 95 

4.80 

5.43 

3.80 

4.93 

30  

5.05 

5.40 

4.83 

4.03 

4.08 

4.20 

2. 95 

4. 75 

4.93 

3.70 

4.90 

31  

4. 95 

5. 05 

3.  90 

3. 95 

2.90 

4.55 

4.77 

Mean  daily  gage  height  of  Tenmile  River  at  Dover  Plains.  X.  )'..  for  1901. 


Day. 


Sept.  Oct. 


1  '   5.02 

2...'  J   4.80 

3..   5.00 

4:..„  |   5.00 

5..  ..          .    i 

6  1  j  4.85 

7  1   4.75 

8  i   4.65 

9  1  1  4.65 

10.  '   4.65 

11   4.65 

12...  '  I  4.65 

13  !  1  4.57 

14  !   6.27 

15  j  j  6.82 

16  !  6.42 


Nov. 


Dec. 


Day. 


Sept, 


.50 


Oct. 


6.17 
5. 87 
5.62 
5.50 
5.  47 
5.40 
5.  SB 
5. 27 
5.  20 
5.00 
5.02 
5.05 
4.97 
1.95 
4.92 


Nov. 


5.05 
5.90 
4.87 
4.87 
4.85 
4.79 
4.75 
4.75 
5.  20 
5.  10 
4.9(1 
4.95 
4.86 
4.72 


Dec. 


8. 15 
7.20 
6.85 
6. 35 
5.95 
5. 75 
5. 92 
5.90 
5.95 
6  40 
6.47 
6.50 
10.70 
12. 30 
10. 22 


pressey.1  GAGE  HEIGHTS.  93 

Mean  daily  gage  height  of  Tenmile  River  at  purer  Plains,  A.  V..  for  I'.n>,.\ 


9 .. 
10.. 
11  .. 
12.. 
13.. 

14  .. 

15  .. 

16  .. 
17.. 
18.. 
19.. 
20.. 
21  .. 
22.. 
23.. 
24.. 
25.. 
26.. 
27  .. 
28.. 

29  .. 

30  .. 

31  .. 


Day. 


Jan. 

Feb. 

Mar. 

Apr. 

May. 

June. 

July. 

Aug. 

Sept. 

Oct. 

Nov. 

Dec. 

7.70 

5.40 

14. 15 

6.60 

6.95 

4. 55 

4. 45 

5. 10 

3.90 

5. 78 

5. 75 

4.45 

7.00 

6.10 

14.10 

6.45 

6.95 

4.50 

4.25 

4.88 

3.  S3 

5. 65 

5.50 

4.4S 

(».  95 

6.95 

all. 43 

6.26 

6. 60 

4.40 

4. 35 

165 

3.  SO 

5. 43 

5.  43 

180 

6.10 

6.08 

8.35 

5.98 

6.20 

4. 55 

5. 53 

4.63 

3.90 

5. 10 

5.  33 

4. 90 

G.W 

5.  SO 

6.95 

5.80 

6. 05 

4.48 

4.38 

153 

3.83 

5.30 

5;  30 

4.73 

6. 15 

5.35 

5.90 

5.90 

5.  IK) 

4.35 

4.60 

4.43 

3.80 

5. 85 

5. 85 

4.78 

(i.  10 

5. 10 

6.25 

6.13 

5.  75 

4.25 

4.63 

165 

3.85 

5.38 

5.  10 

4.80 

5.80 

5. 10 

6.25 

6.40 

5.55 

4.48 

4.33 

4.60 

3.88 

5.  13 

5.08 

4.85 

5.65 

4.95 

8.90 

6.80 

5.35 

155 

4.38 

4.  45 

3. 95 

4. 80 

5. 00 

5. 13 

5.55 

4.90 

10.60 

7.60 

5.23 

4.48 

4.23 

4.43 

4.23 

4.83 

4.93 

5.08 

5. 60 

5. 10 

9. 15 

7.10 

4.95 

4.30 

4.20 

5.68 

3.95 

5. 00 

4.  S3 

185 

1  5.55 

5.10 

8.70 

6.60 

4.85 

4.20 

4.10 

5.03 

3.90 

6. 10 

4.78 

4.80 

5.38 

4.80 

9. 10 

6.30 

4.85 

4.  75 

4. 15 

5. 95 

4.10 

6.93 

4.83 

4.80 

5. 25 

6. 75 

8.40 

6. 15 

4.80 

4.  70 

3.90 

4.78 

4.23 

5.87 

4.80 

4.93 

5. 25 

5.25 

7.70 

6.10 

4.80 

4.-35 

3.88 

4.68 

4.13 

5.63 

4.83 

5.08 

4.93 

5.15 

7.30 

5.90 

4. 75 

4. 45 

4.30 

4.23 

4.03 

5. 43 

4.73 

6. 15 

4.65 

5.05 

8. 15 

5.88 

4. 65 

4.65 

4.18 

4. 18 

3.88 

5.25 

4.65 

10.47 

5.05 

5.05 

7.60 

5.68 

4.60 

4.45 

3.88 

4.15 

3.88 

5.15 

9. 13 

5.10 

5.00 

6.55 

5.58 

4.65 

4.28 

4.03 

4.15 

4.a3 

5. 27 

4.60 

8.28 

5.05 

4.85 

6.13 

5. 45 

4.68 

4.15 

4.65 

4. 18 

4.28 

5. 20 

4. 53 

7.70 

5.05 

4.75 

6. 10 

5.a5 

4.58 

4.40 

6.98 

4.25 

4.33 

4.90 

4.55 

7.74 

1 1  95 

4  68 

g  ],-, 

5. 23 

4. 50 

4  60 

7. 15 

4. 23 

-t.  lo 

4. 80 

4. 58 

11  50 

8.10 

4.40 

6.20 

5. 13 

4.40 

4.38 

6. 35 

4.10 

4. 15 

4.75 

4.55 

10.65 

6.a5 

■i.  'Ml 

6.25 

5  03 

4.30 

4.  oo 

5.  75 

4.08 

a.  na 

4.73 

A  =Q 
*.  OO 

o.  ao 

5.80 

4. 65 

6.05 

4. 95 

4. 30 

4. 15 

5. 68 

4. 08 

4.05 

4. 65 

4.58 

7. 95 

5. 70 

5.83 

5.90 

4.95 

5.05 

4.10 

5.  .50 

3.98 

108 

4.55 

4.70 

7.48 

7.80 

8.45 

5. 85 

5.30 

5. 30 

4.05 

5.30 

3.93 

4.65 

4.60 

4.93 

7.05 

7. 45 

9.73 

7.43 

5. 25 

5. 50 

4.05 

5.40 

3.85 

6.50 

7  05 

4.78 

*;.  .V) 

7.60 

5.30 

5.18 

4.10 

5. 25 

3. 83 

7.75 

7. 10 

4.65 

<f.  25 

7.30 

7.00 

4.80 

4.70 

5.65 

3.80 

5. 98 

6.37 

4.33 

5.50 

6.90 

4.70 

5. 25 

3.85 

6.00 



"  Readings  on  new  gage  from  this  date,  datum  0.33  above  former  gage. 
Daily  gage  height  of  Housatonie  River  at  Gaijlordsville,  Conn.,  for  1900. 


Day. 


Oct. 


Nov. 


'  Dec. 

4.9 
4.6 
4.3 
4.2 
5.6 
5.8 
5.4 
5.1 
4.9 
4.5 
4.2 
4.2 
4.2 
4.2 


Day. 


Oct. 


Nov.  Dec. 


3.1 
3.2 
3.1 
3.1 
3.1 
3.1 
3.0 


3.5 
3.6 
3.7 
4.1 
4.0 
3.9 
3. 9 
3.S 
4.6 
5. 5 
5.4 
5.1 
4.9 


18 
5.1 
4.3 
4  2 
4.1 
4.2 
4.0 
3.9 
4.2 


94  FLOW  OF  RIVERS  NEAR  NEW   YORK  CITY.  [no.  76. 

Daily  gage  height  of  Housatonic  River  at  Gaylordsville ,  Conn.,  for  1901. 


Jan. 

Feb. 

Mar. 

Apr.  May. 

June. 

July. 

Aug. 

Sept. 

Oct. 

Nov. 

Dec. 

4.40 

3.20 

3.30 

5.30 

6.20 

 — 

6.20 

3.60 

3. 50 

4.30 

4.30 

4.00 



4.00 

4.00 

3.30 

3.50 

5.30 

6.20 

6.00 

3.50 

3.70 

4.40 

4.20 

4.20 

4. 10 

(a) 

3.30 

3.60 

5.30 

6.40 

5.  70 

3.80 

3.50 

4.70 

4. 50 

4.00 

4.20 

(«) 

3.30 

3.60 

6.10 

6.30 

5. 50 

3.90 

3.40 

4.60 

4.60 

3.80 

4.10 

(«) 

3. 10 

4.10 

6.60 

6.00 

5.50 

3.70 

3.30 

4.60 

4.40 

3. 70 

4.00 

4.50 

3.00 

3.90 

6.50 

5.60 

5.20 

4.00 

3.30 

4. 40 

4.20 

4. 10 

4.00 

4.50 

3.40 

3.90 

7.30 

5.50 

5. 20 

4.00 

3.90 

4.40 

4.00 

3.80 

3.90 

4.40 

3.50 

3.60 

8.30 

5.30 

5. 50 

3.80 

4.  80 

4.40 

3.90 

3.80 

3.80 

4.20 

3.40 

3. 50 

8.00 

5.20 

5.50 

3.80 

4.40 

4.00 

4.00 

3.80 

3.90 

4.40 

3.70 

7.50 

7.80 

5.20 

5. 40 

3.80 

4. 10 

3.90 

4. 00 

3.70 

5.00 

4. 10 

3.50 

8.20 

7.20 

5.70 

5. 20 

3.90 

4.00 

4.00 

3.80 

3. 50 

5.50 

4. 70 

3.30 

7.50 

6. 70 

6.30 

4.90 

4.00 

3.90 

4.20 

3.80 

3.  M 

5.90 

4.00 

3.40 

6.00 

6.50 

6.10 

4.80 

4.00 

3. 70 

4.00 

3.80 

4.80 

5.70 

3.50 

3.70 

5.50 

6.10 

6.00 

4.60 

3.90 

3.70 

4.00 

5. 20 

4.90 

5.80 

3. 70 

3.60 

5.60 

5.90 

5.60 

5.20 

3.60 

3.60 

4.00 

6. 70 

4.70 

8.90 

3.80 

3.40 

5.60 

5.90 

5. 50 

4.70 

3.50 

3. 70 

4.10 

6.00 

4.60 

8.20 

4.40' 

3.40 

4.60 

5.50 

5.30 

4.50 

3.70 

3.60 

4.10 

5.80 

4.50 

7. 80 

4.00 

3.40 

4.60 

5.130 

5.30 

4.20 

3.60 

3.70 

4.70 

5.30 

4.40 

7.50 

3.50 

3.20 

4.80 

5.20 

5.80 

4.30 

3.60 

4.00 

4.50 

5.10 

4.20 

6.80 

3.40 

3.30 

4.80 

5.20 

6.20 

4.20 

3.60 

3.80 

4.40 

4.90 

4.30 

6. 10 

3.80 

3.40 

10.00 

7.30 

6.20 

4. 10 

3.60 

4.10 

4.20 

4.80 

4.20 

5.60 

3.60 

3.50 

8.70 

9. 30 

5.80 

4.00 

3.50 

4.70 

4.20 

4.60 

4.20 

5.10 

3.70 

3.40 

7.40 

8.40 

5.80 

4.30 

3.40 

4.80 

4.00 

4.50 

4. 10 

4.90 

3.50 

3.20 

7.10 

8.50 

5.60 

4.70 

3.60 

4.80 

3.80 

4.40 

4.20 

5.20 

3.60 

3.30 

6.60 

8.80 

6.80 

4.60 

3.60 

6. 80 

3.90 

4.30 

4.60 

5.20 

3.70 

3.00 

6.60 

7. 85 

6.70 

4.1* 

3.50 

6.  70 

3.80 

4.30 

4.8C 

5. 00 

3.80 

3.40 

7.20 

7.20 

6.80 

4.20 

3.50 

5. 70 

3.80 

4.20 

4.50 

5.:* 

3.70 

3.30 

6.90 

6.90 

6.80 

4.00 

3.50 

5.20 

3.80 

4.00- 

4.00 

5. 10 

3.50 

6.60 

7.00 

6.90 

4.00 

3.50 

4.80 

3.90 

4.00 

4.00 

6.30 

3.50 

6.20 

6.40 

6.80 

3.80 

3.40 

4.60 

4.40 

4.30 

4.20 

9.40 

3.40 

5.80 

6.60 

3. 70 

4.40 

4.10 

7.60 

a  Frozen. 


pbessby.]  GAGE  HEIGHTS.  95 


Mean  daily  gage  height  of  Housatonic  River  at  Gaylordsville,  Conn.,  for  1902. 


Day. 

Jan. 

Feb. 

Mar. 

Apr. 

May. 

June. 

July. 

Auk- 

Sept. 

Oct. 

Nov. 

Dec. 

1 

7.10 

4.90 

14. 30 

6.80 

6. 80 

4.  70 

4. 80 

4.80 

3. 80 

5. 50 

5.50 

4.10 

2 

6. 50 

4.90 

10. 80 

6.(50 

6. 30 

4. 40 

4.60 

4.65 

3.55 

5.50 

.">.  30 

4. 15 

g 

5. 90 

5.40 

9.90 

6. 80 

6. 10 

4.40 

4.40 

4.65 

3.50 

5. 25 

5.00 

4.40 

4 

5.30 

I  90 

10.20 

5.80 

5.90 

4.60 

4.  70 

4.45 

3.60 

5. 15 

4.05 

4. 60 

5.20 

4.  so 

7.80 

5.80 

5.60 

4.90 

4.50 

4.30 

3.65 

5.00 

4.85 

4.60 

6   

5.30 

4.60 

6.80 

5.50 

5.50 

4.80 

4.50 

4.40 

3.55 

5. 15 

4.30 

5. 30 

4.50 

6.50 

.">.50 

5.50 

4.60 

4.80 

4.60 

3.65 

5.00 

4.65 

4.35 

s 

5.20 

4.40 

6.80 

5.70 

5.30 

4. 60 

5.00 

4.55 

3.50 

4. 85 

4. 60 

4.30 

9 

5.30 

8.50 

6.80 

6. 10 

5.20 

4.40 

4.  70 

4.55 

3.55 

4.  70 

4.50 

:;.  15 

10 

5. 10 

6.80 

7.50 

6.80 

4.90 

4.60 

4.50 

4.45 

4.00 

4.55 

4.35 

3.55 

11 

5.00 

7.00 

2.20 

6.90 

5.00 

4.50 

4.40 

4.50 

4.00 

4.40 

4.30 

8.70 

12 

4.90 

8.00 

7.70 

6.80 

4.90 

4.50 

4.30 

5.15 

3.90 

5.30 

4. 45 

3.  75 

13 

4.70 

8.80 

7.80 

6.80 

4.90 

4.40 

4.20 

5.00 

3.85 

5.30 

4.40 

4.00 

14 

4.30 

8.30 

8.00 

6.70 

4.80 

4.70 

4.00 

4.70 

4. 10 

5. 10 

4.50 

4.05 

15 

4.50 

8.00 

7.90 

6.20 

4.70 

4.60 

3.90 

4.50 

4.00 

5.00 

4.50 

4.25 

16 

4.50 

7. 10 

7. 70 

5.90 

4.60 

4.30 

4.10 

4.35 

3.60 

4.80 

4.40 

4.90 

17 

4  30 

6.80 

7.90 

5.80 

4.60 

4.50 

4.20 

4.20 

3.70 

4.  75 

4. 35 

7.90 

18   

4.20 

7.00 

7. 60 

5. 00 

4.50 

4.40 

3.90 

4.00 

3.75 

4.  CO 

4. 25 

7.35 

19   

4.40 

7.50 

7.30 

5.60 

4.40 

4.  40 

3.80 

3.80 

3.80 

4.30 

6.70 

20 

4. 20 

7.30 

7.00 

5.50 

4.30 

4.40 

4.65 

4.05 

3,85 

4. 25 

4.25 

6.35 

21 

4.50 

7.20 

6.60 

5.20 

4.60 

4.30 

6.00 

3.95 

4. 05 

4.30 

4.30 

6.65 

22 

8.50 

7.20 

6.60 

5.20 

4.40 

4.  70 

6.60 

4.05 

3. 75 

4.45 

4.20 

8.60 

23 

6.80 

6.80 

6. 10 

5. 10 

4.30 

4.50 

6.00 

4. 10 

3. 60 

4.40 

4.20 

8.40 

24  

6.30 

6.50 

5.90 

5. 10 

4.10 

4.30 

5.70 

4.10 

3.70 

4.45 

4.05 

7.55 

25   

5.80 

6.80 

6.00 

5.00 

4.20 

4.30 

5.50 

3.95 

3.65 

4. 45 

4. 15 

7.30 

26   

5.60 

7.00 

6.00 

4.90 

4.50 

4.30 

5.30 

3.95 

3.85 

4.40 

4.25 

6.90 

27—.  

5.90 

10.60 

5.90 

5.00 

4. 60 

4.20 

4.95 

3. 95 

4. 20 

4.30 

4.60 

6.65 

28....  ,., 

5.70 

9.00 

5.90 

5. 10 

5.30 

4.20 

4.85 

3. 95 

4.60 

5.85 

4.50 

6.00 

29   

gjap 



6.70 

5. 10 

5.20 

4.10 

5.55 

3.90 

6.30 

6.55 

4.40 

5.75 

30   

4.90 

6.70 

6.20 

5.00 

4.30 

5. 45 

3.90 

6.00 

6.00 

4.25 

5.90 

31  

4.90 

6.70 

4.70 

5. 40 

3.70 

5.80 

5.60 

96 


FLOW  OF  RIVEKS  NEAR  NEW  YORK  CITY. 


[NO.  7ti. 


( 'urrent-meter  discharge  measurements  of  Catskill  Creek  at  South  ( 'airo,  X.  Y. 


Date. 

Gage 
height. 

Discharge. 

Hy  drographer . 

1901. 

Feet. 

Second-feet . 

Oct.  10 

2.58 

23.3 

Hollister  and  Schlecht. 

Oct.  4 

2.70 

25.6 

W.  W.  Schlecht. 

Nov.  8  . 

2.70 

27.6 

Do. 

Aug.  19 

2.70 

39.6 

Hollister  and  Place. 

2.74 

35. 6 

W.  W.  Schlecht. 

Nov.  9 

2.  75 

42.3 

Do. 

July  4 

2. 75 

60.9 

Horton  and  Hollister. 

Aug.  1 

2.80 

47.9 

A.  E.  Place. 

Oct.  22 

2.82 

54.2 

W.  W.  Schlecht. 

Sept.  7 

2.92 

68.8 

A.  E.  Place. 

Aug.  9 

3.00 

81.5 

Do. 

July  25 

3.00 

81.9 

Do. 

Sept.  2 

3.00 

87 

Do. 

Aug.  27 

3.12 

121.4 

Do. 

July  17 

3.  50 

260.3 

Pressey  and  Place. 

July  20 

3.60 

307.  5 

A.  E.  Place. 

June  13 

2.69 

40.6 

W.  W.  Schlecht. 

June  24 

2.70 

43. 5 

Do. 

Aug.  27 

2.74 

39.4 

H.  K.  Barrows. 

Sept.  5 

2.79 

50 

Do. 

June  3 

2.82 

49.  5 

W.  W.  Schlecht. 

May  23 

2.83 

51.1 

Do. 

Sept.  22 

3.32 

121 

P.  M.  Churchill. 

July  9 

3.365 

113.5 

H.  K.  Barrows. 

May  10 

3.47 

133 

W.  W.  Schlecht. 

Aug.  13 

3.49 

135 

H.  K.  Barrows. 

Nov.  7 

3.80 

235 

F.H.Tillinghast. 

Dec.  3 

3.90 

275 

Do. 

Oct.  10 

3.92 

242 

P.  M.  Churchill. 

4.06 

320. 2 

W.  W.  Schlecht. 

Aug.  2 : 

5.36 

1,005 

H.  K.  Barrows. 

July  23 

6.11 

1.602 

Do. 

Apr.  11 

6.86 

2,312 

W.W.  Schlecht. 

Mar.  13 

8.66 

5, 483 

Horton  and  Schlecht. 

A  measurement  made  February  27, 100:!,  with  the  stream  obstructed 
by  Lee,  showed  the  discharge  363  second-feet,  gage  he  ghl  4.7l\  The 
stream  was  frozen  from  bank  to  bank  to  a  depth  of  G  to  8  inches. 


PRESSJ3Y.]  DISCHARGE  ME  A  S  U  RE  MENT3 .  97 

Current~meter  discharge  measurements  of  Esopus  ( 'reek  at  Kingston,  X.  Y. 


Date 


1901. 

Aug.  5  

July  22.  ,  

July  18  

July  5  

July  19  

Nov.  18  

Sept.  26   

Do  

Aug.  19  

Oct,  10  

Do  

Oct.  8    

Nov.  1   

Nov.  14  

Sept.  21  

Aug.  10  

Nov.  26  ___s  

Oct.  3   

Sept.  6  

Aug.  29  

Oct.  21  |  

Aug.  8  .....  

Sept.  4   

Aug.  27  ... 

Oct.  16.   

Dec.  19.   

Dec.  11   

Dec.  30    

1902. 

June  10   

Sept.  4  

Aug.  21    

June  26  .  

June  5  

July  16  .  

Nov.  22    

July  9    

May  14...  

Sept,  23  

IRR  76—03  7 


(  rHgl' 

height. 

Discharge. 

Hydrographer. 

Feet. 

s<'ctm(l-feet. 

3.  60 

OA  A 

\     TJ1  Til.. 

A.  E.  PJa<<'. 

3.  80 

O  i  a 

64.  2 

Do. 

4. 10 

144.  9 

Do. 

4.  32 

148 

Jbiorton  and  Holiister. 

4.  40 

172.  7 

A.  Ei.  Place. 

4.  4.) 

126.  5 

W .  VV .  fecnleclit. 

4.  55 

167. 8 

Do. 

4.  .).) 

150.  4 

Do. 

4.  ()0 

180.  2 

riollister  and  Plare.  . 

4. 62 

165;  's 

VV .  VV  .  bclnecht. 

4.  b~Z 

ISS.  1 

(J-eo.  13.  Mollister. 

4.  <0 

1  <8.  2 

ITT     TXT     CS.  1,"!  .^.,1. -4- 

W .  VV .  bcnlecnt. 

4. 74 

184.  3 

Do. 

4.  Jo 

[)>■).  4 

TA  ^ 

Do. 

.  4.  <o 

200.  3 

Do. 

4.  8.) 

259.  2 

A.  E.  Place. 

5.  06 

244. 7 

VV .  \V  .  bcnlecnt. 

5.  26 

329.  4 

Do. 

5. 46 

352. 2 

A.  E.  Place. 

5  .  50 

364.  3 

Do. 

5. 56 

380. 8 

W.  VV .  bcnlecnt. 

5.  65 

396. 1 

K       TT*     TH  ^  

A.  E.  Place. 

6.11 

554.  3 

Do. 

6.26 

728.  6 

Do. 

(5.  04 

785.  2 

ITT      "ITT      t1      1,1           I  J 

W.  \\  .  Schlecnt. 

8.35 

1 , 472 

Do. 

11.46 

1, 720, 8 

Do. 

12. 15 

3, 989^ 

Do. 

4.  48 

135. 8 

W.  W.Sehlecht. 

4. 49 

133 

H.  K.  Barrows. 

4.  94 

191 

Do. 

5. 02 

225 

TTT       TTT       till              1  . 

W.  \\  .  Schlecnt. 

5.  03 

234.  5 

Do. 

5. 13 

268. 8 

H.  K.  Barrows. 

5.  45 

272 

F.H.Tfflinghast. 

5.  81 

450.  4 

Barrows  and  Schlecnt. 

5.83 

422 

W.  W.Sehlecht. 

5. .87 

449 

P.  M.  Churchill. 

"98  FLOW  OF  RIVERS  NEAR  NEW  YORK   CITY.  [no.  76. 


Current-meter  discharge  measurements  of  Esapus  Creek,  etc. — Continued. 


Date. 

Gage 
lioi  lit 

Discharge, 

Hydrographer. 

MM  12. 

Feet. 

Second-fke^t. 

±y  ( >  \  .  1  i  

6 

416 

F.  H.  Tillinghast . 

Aug.    1~  - 

6.28 

550 

H.  K.  Barrows. 

May  24 

6.  88 

«274 

W.  W.  Schlecht. 

6.41 

a  272 

Do. 

Hov  5 

6.  56 

594 

F.H.  Tillinghast. 

Aim 

6.94 

828. 3 

W.W.  Schlecht. 

Mav  14 

7.14 

<?  508 

Do. 

July  30  . 

7.65 

1.  155 

H.  K.  Barrows. 

.July  34 

8.11 

1.348 

Do. 

Oct.  4 

1  QOA 

J  .  Di.  v  nine  lull. 

Mar.  12 

9.  90 

2. 843 

Horton  and  Schlecht. 

10.28 

2.813 

W.  W.  Schlecht. 

Apr.  10 

18. 37 

5,021 

Do. 

Mar.  1 

20. 38 

M2.620 

Do. 

a  Measured  at  Glasgow  Bridge.  Glen  Eyrie. 

''Large  quantities  of  floating  ice  in  the  stream.   Surface  velocities  txsed. 


The  following  measurements  were  also  made  during  the  period  of 
dee  obstruction  by  W.  W.  Schlecht: 

February  20:  Gage  height,  5.38;  discharge,  245  second-feet;  river 
partly  fro/on  over.  February  15:  Gage  height,  5.60;  di  soli  a  rue  557 
second-feet ;  river  mostly  frozen  over.  February?:  Gage  height,  G.83; 
discharge,  ^30  second-feet;  river  partly  frozen.  September  29,1.30 
p.  m. ,  the  stream  attained  a  flood  stage,  giving  a  reading  of  25.25  on 
the  gage. 

Current-meter  discharge  measurements  of  Rohdout  Creek  at  Rosendale,  X.  Y. 


Date.  heh^ht       Discharge.  Hydrographer. 


1901. 

Feet. 

Second-feet. 

-July  18  

fi.  80 

118.2 

A.  E.  Place 

Aug.  6   

6.40 

99.4 

Do. 

Nov.']   

«.  42 

138.2 

W.  W. $chlecht 

Sept.  24   

6.45 

1:59.6 

D«». 

Oct.  n  ;  

6.47 

163.2 

Do. 

Oct.  n  

6.  47 

201.  8 

G.B.Hollister. 

Nov.  16 

6.  55 

183 

W.W.ScKtecht 

.bily «...   

('..  55 

319 

Horton  and  Efcllister 

Aug.  15  

6.  55 

225.  4 

A.  E.  Place. 

Oct.  7.    

6.  60 

217.5 

W.  W.ScMecht. 

prbssxt.]  DISCHAKGE  MEASUREMENTS.  (.>c.> 

Current^mcter  discharge  measurements  of  Rondout  <  'reek,  etc. — Continued. 


Date. 


Sept  7  . 
Aug.  20 
Oct.  18. 
Aug.  28 
Aug.  S  _ 
Sept.  4  . 
Dec.  21. 
Sept.  3  . 
Dec.  12. 
Nov.  26 
Dec.  30 . 


1901. 


1902. 


Gage 
height. 


Discharge. 


Frrt. 
<>. 


11.  o: 


8econd-feet. 
426.7 

526.4 

509. 0 

644  6 

74.").  4 

836.1 

772 

1 . 200 

1 . 490. 8 

675.4 

5, 353 


Hydrographer 


A.  E.  Place. 
Hollister  and  Place. 
W.W.  Schlecht. 
A.E.Placv. 

Do. 

Do. 

W.  W.Schlecht." 
A.  E.  Place. 
W.  W.  Schlecht. 
Do. 

Do/' 


Sept.  25  

6.31 

167 

B.  M.  Churchill. 

July  15   

6.33 

141.9 

H.  K.  Barrows. 

6.33 

137.2 

Do. 

6.33 

145 

Do. 

June  6  

6.38 

163 

W.  W.  Schlecht. 

June  20  

6.42 

166 

Do. 

Nov.  21  _..  . 

6.55 

283.4 

F.  H.  Tillinghast. 

Dec.  2  

6.70 

367 

Do. 

Apr.  28  j*  

6.83 

382 

W.  W.  Schlecht. 

May  12  

().  855 

421 

Do. 

Nov.  4  

7.00 

570 

P.  H.  Tillinghast. 

Aug.  7  

7.39 

838 

H.  K.  Borrows. 

7.  40 

888 

Do. 

Mar.  21  

8.07 

1.529 

W.  W.  Schlecht. 

17.60 

13.936 

Do. 

Apr.  11  

11.78 

5. 666 

Do. 

n  Stream  somewhat  obstructed  by  shore  ice. 

Additional  measurements  were  made  by  W.  W.  Schlechl  while  the 
river  was  frozen  over,  as  follows: 

February  18,  gage  height,  7.7<»;  discharge,  342  second-feet.  The 
river  was  frozen  over  from  bank  to  bank  and  slush  had  collected 
below  the  ice. 

February  :?<*,,  gage  height,  8.13;  discharge,  543  second-feet.  Slush 
below  the  ice  made  an  unsatisfactory  record. 

February  26,  gage  height,  8,43;  discbarge,  684  second-feet.  Ice  cov- 
ered the  river  from  bank  to  bank  and  slush  had  collected  underneath. 


100 


FLOW   OF   RIVERS   NEAR  NEW   YORK  CITY. 


[xo.  76. 


The  Delaware  and  Hudson  Canal  has  been  abandoned  in  New  York 
Slate,  with  the  exception  of  the  portion  from  High  Falls  feeder  on 
Rondonl  Creek  to  tide  water,  below  Eddy ville.  The  gaging  station  at 
Rosendale  is  situated  opposite  the  canal  level  between  locks  6  and  7. 
The  water  supply  of  this  level  is  drawn  entirely  from  Rondout  Creek. 
In  order  to  determine  the  amount  of  this  diversion  during  the  season 
of  canal  navigation,  usually  from  April  1  to  December  10,  a  record 
has  been  kept  at  lock  Xo.  6,  or  Creek  Locks,  at  the  lower  end  of  t  he 
Rosendale  level.  The  record  includes  overflow  at  by-pass  weir,  water 
used  for  lockage,  and  flow  through  paddles  in  miter  gates.  There  is 
also  a  small  amount  of  leakage  in  the  lock  walls  and  gates  which  has 
not  been  determined.  The  flow  in  the  canal  at  lock  Xo.  <>  added  to 
the  flow  at  the  Rosendale  station  will  give  the  total  actual  run-off 
from  Rondout  Creek  above  Rosendale.  The  following  tables  show 
the  mean  monthly  and  estimated  daily  diversion  during  the  canal 
season  of  1902.  The  estimated  flow  in  the  canal  as  recorded  in  L901 
is  as  follows: 

Second-feet. 

October.  1901   20 

November  21.  1901  :   19 

Mean  monthly  diversion  in  second-feet  to  Delaware  and  Hudson  Canal,  lock  No.  6, 

near  Rosendale,  in  190.2. 

Second-feet 

March  Q  ,  •....15.70 

April  1  "A  22.45 

May  r  29.98 

June  23. 67 

July  .   23.78 

August  .   24.33 

September  .  &  .....  23. 99 

October   22. 23 

Current-meter  measurements  of  Wallkill  Hirer  at  yen-  Paltz,  X  Y. 


Date. 


1901. 

Nov.  9  

July  23  

Oct.  11-.- 
Oct.  11 .. 

Oct.  24  

Oct.  9  

Nov.  16  

July  7.  

JulyS  


Gage 
height. 

Discharge. 

Feet. 

Second- feet. 

5.94 

178 

5. 20 

306 

0.  30 

340 

6.30 

355 

6.33 

333 

6.48 

398 

6.  50 

402 

7.19 

824 

7.25 

842 

Hydrographer. 


"  March     to  31,  inclusiv< 


W.W.Schlecht. 
A.  E.  Place. 
W.W.Schlecht. 
Geo.  B.  Holliste- 
W.W.Schlecht. 

Do. 

Do. 

Horton  and  Hollister. 
Do. 


pkissky]  DISCHARGE  MEASUREMENTS.  101 

Current-meter  measurements  of  Wallkill  River  at  New  Pattz,  X.  Y. — Continued. 


Date. 


1901. 


Oct 
Nov. 
Sept. 
Aug. 
July 
Sept. 
Aug. 
Aug. 
Aug. 
Dec. 
Dec. 
Aug. 

July 
Aug. 
Sept. 
June 
May 
June 
Nov. 
May 
Aug. 
Dec. 
Apr. 
Feb. 
July 
Apr. 
Feb. 
Nov. 
Aug. 
May 
Apr. 
Mar. 


1  .. 
27  _ 
19 
13 
19. 
5  . 
31 
20 
28 
11. 
19. 


ir. 

28 
18 
19 
21. 
6  . 
18 
13. 
15 
o 

20 
21  _ 
29. 
21 
10. 
4  . 
6  . 
1.. 
9  . 
11 


1902. 


(^age 
height. 

Discharge. 

Hydrographer. 

Feet. 

Second-feet. 

7.36 

896 

W.W.  Schlecht. 

7.52 

1,022 

Do. 

7.73 

.  1.076 

Horton.  Place,  and  Schlecht. 

7.8r, 

.  1,038 

A.  E.  Place. 

8.25 

1.243 

Do. 

8.90 

1.676 

Do. 

9. 07 

1,917 

Do. 

10.00 

2  729 

Hollister  and  Pla  • 

10.60 

2.  982 

A.  E.  Place. 

11.50 

3,040 

W.W.  Schlecht." 

13.70 

3.277 

Do/' 

14.85 

7, 365 

A.  E.  Place. 

5.70 

124.  3 

H.  K.  Barrows. 

5.86 

169 

Do. 

5. 96 

209.  5 

Barrows  and  Churchill. 

6.18 

295 

W.  W.  Schlecht. 

6.33 

344 

Do. 

6.40 

381 

Do. 

6.62 

550 

F.  H.  Tillinghast 

6.68 

506 

W.  W.  Schlecht. 

6.72 

518 

H.  K.  Barrows. 

6.80 

626 

F.  H.  Tillinghast. 

6.92 

&680 

W.  W.  Schlecht. 

7.33 

288 

Do. 

7.49 

942 

H.  K.  Barrows. 

7.  57 

<U.028 

W.  W.  Schlecht 

7. 78 

597 

Do. 

7.95 

1. 165 

F.  H.  Tillinghast. 

7.98 

'  1.150 

H.  K.  Barrows. 

10.264 

2.628 

W.  W.  Schlecht. 

13.  21 

5.354 

Do. 

15.93 

7.140 

Do. 

a  Stream  obstructed  by  ice  causing  backwater. 

Measured  through  ice  1  foot  0  inches  t<> feet  6  inches  in  thickness 
'•Measured  through  ice  1  foot  to  2  feet  in  thickne^>. 


102 


FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY. 


[no.  76. 


Current  meter  measurements  of  Fishkill  Creek,  at  Glenham,  Dutehess  County, 

N.  Y. 


July  24. : 
Oct,  12  . 
Nov.  11 
Aug.  15 
Sept.  27 
July  20 
July  S.- 
Nov. 20 
Oct.  5  .  _ 
Oct.  15  . 
Sept.  6  . 
Sept.  18 
Dec.  24. 
Aug.  21 
Aug.  30 
Dec,  13. 
Oct.  15 . 
Dec.  31  _ 


Aug.  26 
July  14. 
Aug.  1  1 
Oct.  11. 
June  2  . 
July  28. 
June  1 7 
Nov.  8  . 
Apr.  25 
May  6.. 
Feb. 11. 
Oct.  30. 
Apr.  12 
Mar.  5 


Date. 


1901. 


11)02. 


Gage  height 


Discharge. 


Hydrographer. 


Feet. 

Second-feet . 

3  fiO 
o.  oo 

60 

A.  E.  Place. 

O.  oU 

97 

Geo.  B.  Hollister. 

82 

W.  W.  Schlecht. 

O.  oO 

in/ 

A.  E.  Place. 

6  OA 

0.  oo 

90 
w 

W.  W.  Schlecht. 

Q  on 

1  as 

100 

A  E  Place 

'»  OO 

0. 

147 

Horton  and  Hollister. 

Q  QX 
O.  Vr> 

114 

W.  W.  Schlecht. 

O.  OO 

126 

Do. 

1  Ot 

■i.  UO 

137 

Do. 

4.15 

193 

A.  E.  Place. 

4.22 

229 

Do. 

4.52 

315 

W.  W.  Schlecht, 

4.  56 

342 

A.  E.  Place. 

4.60 

3.5 

Do. 

4.  62 

3<5 

W.  W.  Schlecht. 

5.10 

579 

Do. 

7.43 

2,210 

Do." 

3.  04 

48.5 

3.18 

64.4 

3.51 

115 

3.71 

155 

3.  785 

132.  3 

3.90 

200 

4.00 

212. 5 

4.00 

233 

4.  03 

M52.4 

4.46 

349.  5 

4.87 

^202.5 

4.97 

697.7 

5.30 

772.6 

5.79 

1.  129 

H.  K.  Barrows. 
Do. 

Do. 

P.  M.  Clmi-chill. 
W.  W.  Schlecht. 
H.  K.  Barrows. 
W.  W.  Schlecht. 
F.  H.  Tillinghast. 
W.  W.  Schlecht. 

Do. 

Do. 

C.  C.  Covert. 
W.  W.  Schlecht. 
Do. 


o Surface  velocity  used. 

&  Probably  incorrect.  '  '  ^  _ 

olcc  along  banks  at  gaging  station,  frozen  from  hank  to  hank  90  yards  below  station  I  to 

9  inches  thick. 


PKESSEY.] 


DISCHARGE  MEASUREMENTS. 


103 


Current-meter  discharge  measurements  of  Tenrkile  River  <if  Tcibor's  bridge,  below 

Borer  Plains,  N.  Y. 


Date. 

Gage 
height. 

Discharge. 

Sydrographer. 

1901. 

Feet 

Second-feet. 

Sept.  16 

5.  27 

245.  4 

A.  E.  Place. 

4.30 

70.3 

W.  W.  Schlecht. 

Nov.  11 

4.  75 

121.5 

Do. 

Nov.  32 

4.70 

123.  4 

Do. 

Nov.  22 

4.  76 

120.9 

Do. 

Nov.  G 

4.88 

140.  1 

Do. 

Oct.  26 

5.01 

187.0 

Do. 

Dec.  27 

0.54 

554 

Do. 

Oct.  15 

7.19 

692.8 

Do. 

Dec.  17 

8.41 

1,213.4 

Do. 

1902. 

Sept.  2 

3.  95 

63 

H.  K.  Barrows. 

Aug.  19 

4.28 

100 

Do. 

June  10  . .  _ 

4.45 

« 158 

W.W.  Schlecht 

Feb.  13 

4.07 

179 

Do. 

Aug.  4 

4.09 

184.8 

H.  K.  Barrows. 

Nov.  28 

4.80 

211.5 

F.  H.  Tillinghast. 

Nov.l4_.  _ 

4.87 

211 

Do. 

May  15 

4.88 

230 

W.W.  Schlecht. 

June  30 

4.  92 

249 

Do. 

May  28. 

5.50 

380 

Do. 

Oct.2 

5.80 

443 

P.M.Churchill. 

0.13 

520 

W.W.  Schlecht. 

Apr.  7  

0.18 

558 

Do. 

May  2  

0.40 

040 

Do. 

July  21.... 

7.18 

821 

H.  K.  Barrows. 

Mar.  3 

10.41 

2,  386 

W.W.  Schlecht. 

«  River  nearly  covered  with  ice  from  bank  to  bank  and  li  to  2i  inches  thick. 


104  FLOW  OF  RIVERS  NEAR  NEW  YORK  CITY.  [no.  76. 

C a rro nt-meter discharge 'measurements  of  Housaton  ic  River  at  Gaytorelsville,  Conn. 


wr 

Date. 

Gage 
height. 

T  )is< 

H  Y(ll'Oi£l*(ipll©l*. 

1900. 

Feet. 

Second- feet. 

Oct  °0 

3 

303 

E.  G.  Paul. 

Oft  91 

3.10 

370 

Do. 

A  no-  10 

3.25 

422 

Do. 

3.  30 

450 

Do. 

1901 . 

3. 50 

549.  5 

A.  E.  Place. 

ftpnt  28 

3.78 

700.  8 

W.  W.  Srhlecht. 

Sprit  1 3 

4 

911.7 

A.  E.  Place. 

Oct  29 

4. 05 

951 

W.  W.  Schlecht. 

Nov  23 

4.11 

965.4 

Do. 

Nov  13 

4.82 

1,863.7 

Do. 

Dec.  28 

5. 16 

2, 250 

Do. 

1902. 

Sept  8 

3. 45 

543 

H.  K.  Barrows. 

Rent  19 

3.75 

640 

Barrows  and  Churchill. 

Alio-  20 

3.  95 

835 

H.  K.  Barrows. 

4.  28 

983 

Do. 

July  11 

4.30 

1,159 

Do. 

Nov.  29 

4.40 

1.281 

F.H.  Tillinghast. 

June  23 

4.46 

1. 177 

AY.  W.  Schlecht. 

Nov.  15 

4.  50 

1,356 

F.H.  Tillinghast. 

Oct.  3 

5.  35 

2?  133 

P.  M.  Churchill. 

May  3 

6.10 

4, 459 

W.  W.  Schlecht. 

July  22 

6.  68 

5.119 

H.  K.  Barrows. 

Mar.  18 

7.63 

8,  259 

W.  W.  Schlecht. 

Mar.  4 

9.9 

13.601 

Do. 

IND 


EX. 


Page. 

Abbott.  H.  L..  and  Humphreys.  A.  A.. 

cited  on  form  of  vertical  ve- 
locity curve   22 

reference  to  20. 46 

Alkalinity,  method  of  determining   7 1 > 

of  streams  discussed,  diagram  show- 
ing ...   76 

table  showing   77-85 

Allen.  C.  J.,  work  of    62 

Austin.  Tex.,  hydraulic  plant  at.  failure 

of     10 

Babb.  C.  C,  reference  to    20 

Bear  Valley  dam,  California,  lack  of 

water  in    11 

Birdsall,  G.  X.,  measurements  suggested 

by   13 

( 'atskill  Creek,  alkalinity  observations  on. 

diagram  showing  results  of. . .  76 
color  observations  on.  diagram  show- 
ing results  of    74 

discharge  measurements  of  .    M 

gage  heights  of    87 

gaging  station  on,  description  of  27-28 

view  of  .A   26 

hardness  observations  on,  diagram 

showing  results  of   78 

quality  of  water  of,  table  showing  ...  77 
turbidity  observations  on,  diagram 

showing  results  of   70 

velocities   in   vertical  sections  on. 

tables  showing  39-40, 45 

under  ice.  tables  showing.   58 

velocity  at  mid  depth  and  mean  ve- 
locity on,  relation  between   16 

.  vertical  velocity  curve  for,  diagram 

showing   24 

Color,  methods  of  determining   73-7t> 

of  streams  discussed,  resxiltsof  obser- 
vations of,  diagram  showing. .  74 

table  showing    77-85 

standards  for  determining   74-75 

tul  >es  and  disks  for  determining  plate 

showing   72 

Cunningham,  Allan,  cited  on  velocity  of 

rod  floats   18 

Current  meter,  plate  showing   20 

use  of.  in  determiniir:  velocity   in  20 

view  showing   18 

Dams,  use  of.  in  determining  velocity   18-19 

Darcy,  H..  formula  derived  by   26 

De  Pronv.  work  of   26 


Page. 

Discharge   measurements,  methods  of 

making,  views  of   18 

tables  of   96  104 

Disks    for    measuring    color   of  river 

water   72 

Dover  Plains,  gaging  station  at.  descrip- 
tion of   29 

Tenmile  River  at,  discharge  measure- 
ments of   103 

gage  heights  of   92-93 

velocities  in  vertical  sections  on. 

tables  showing   43,45 

Ellis.  T.  G.,  reference  to   20,46 

Esopus  Creek,  alkalinity  observations 
on,  diagram  showing  results 

of    76 

color  observations  on,  diagram  show- 
ing results  of   74 

curves  of  equal  velocity  on,  diagram 

showing   22 

discharge  measurements  of.   ^7-08 

gage  heights  of    88 

gaging  station  on,  description  of   28 

view  of   26 

hardness  observations  on,  diagram 

showing  results  of.    78 

quality  of  water  of,  table  showing.  83-81 
turbidity  observations  on,  diagram 

showing  result  of   70 

velocities  in  vertical  sections  on.  tables 

showing    32-34,45 

under  ice,  table  showing   54-55,63,64 

velocity  at  mid  depth  and  mean  ve- 
locity on,  relation  between   46 

vertical  velocity  curve  for.  diagram 

showing.   24 

under  ice  cover,  diagram  show- 
ing   61 

Fishkill  ('reek,  alkalinity  observations 
on,  diagram  show  ing  results 

of   76 

color  observations  on,  diagram  show- 
ing results  of  . .   74 

discharge  measurements  of.   108 

gage  heights  of  91-92 

gaging  station  on.  description  of   28 

hardness  observations  on,  diagram 

showing  results  of   78 

quality  of  water  of,  table  showing  . . .  82-84 
tnrliidity  observations  on,  diagram 

showing  result  of   70 

105 


106 


INDEX. 


Page. 


Fishkill  Creek,  velocities  in  vertical  sec- 
tions on,  tables  who  whit; . . .  41-42, -to 
velocity  at  mid  depth  and  mean  ve- 
locity on,  relation  between   40 

vertical  velocity  curve  for,  diagram 

showing    24 

Floats,  methods  of  using,  to  d3termine 

velocity     15-18 

Flow,  estimates  of,  variation  in  -  -  12 

Francis,  J.  B.,  cited  on  velocity  of  rod 

floats     17 

formula  for  determining  velocity  by.  18 

reference  to    19 

Freeman,  J.  R.,  reference  to    19 

Fteley ,  A . ,  and  Stearns,  F .  P . ,  reference  to .  19 

Gage  heights,  tables  showing   87-95 

Gaging  stations,  views  of    26,28 

Gaylordsville,  Conn.,  gaging  station  at, 

description  of    29 

gaging  station  at,  view  of _    28 

Housatonic  River  at,  discharge  meas- 
urements of  :    1U4 

gage  heights  of    93-95 

velocities  in  vertical  S3ctk>ns  on, 

tables  showing   44 

Gila  Bend,  Ariz.,  failure  of  dam  ct   11 

Glenham,  gaging  station  at,  description 

of  -—  28 

Fishkill  Creek  at,  discharge  measure- 
ments of  _   102 

gage  heights  of  91-92 

velocities  in  vertical  sections  on, 

tables  showing    41-42, 45 

Gordon,  R.,  work  of  ..   2(3 

Hardness,  method  of  determining  76-77 

of  streams  discussed,  diagrams  show- 
ing   78 

tables  showing   77-85 

Hazen,  Allen,  method  of  determining 

color  devised  by . .  -   73 

Horizontal  velocity  curves  on  Wallkill 

River,  diagram  showing   30 

Hoitsatonie  River,  alkalinity  observa- 
tions on,  diagram  showing  re- 
sults of   76 

color  observations  on,  diagram  show- 
ing results  of   74 

discharge  measurements  of.   104 

gage  heights  of  .    93-95 

gaging  station  on,  description  of   29 

view  of     28 

hardness  observations  on,  diagram 

showing  results  of   78 

quality  of  water  of,  table  showing  84-85 

turbidity  observations  on,  diagram 

showing  results  of .   70 

velocities   in  vertical   sections  on. 

tables  showing   44 

velocity  at  mid  depth  and  mean  ve- 
locity on,  relation  between   46 

vertical  velocity  curve  for,  diagram 

showing   24 

Humphreys,  A.  A.,  and  Abbott,  H.  L., 
cited  on  form  of  vertical  ve- 
locity curve   22 

reference  to   20,4(5 


Page. 


let",  broken  and  tilted,  flow  of  rivers 

under   64 

smooth  and  unbroken,  flow  of  rivi-rs 

under   48-64 

Jackson,  D.  D.,  and  Whipple,  G.  C,  refer- 
ence t  o    71.72 

Jellys  Ferry,  Cal.,  Sacramento  River  at. 

relation  of  mean  and  surface 

velocity  on..    23 

Kingston,  gaging  station  at,  description 

of..   28 

gaging  station  at,  view  of   26 

Esopus  Creek  at,  curves  of  equal  ve- 
locity on,  diagram  showing ...  22 

discharge  measurements  of  97-98 

gage  heights  of   88 

velocities  in  vertical  sections  on, 

table  showing   32-34 , 45 

Lagrange,  Cal.,  Tuolumne  River  at,  re- 
lation of  mean  and  surface  ve- 
locity on   23 

Lippincott,  J.  B.,  quoted  on  velocity 
curves  on  rivers  in  southern 

California     23 

Measurements,  method  of  making,  views 

of   18 

Meter.   See  Current  meter. 

Mississippi  River,  vertical  velocity  curve 

on,  form  of.   22-23 

Murphy,  E.  C,  reference  to   20 

j  New  Paltz,  gaging  station  at,  description 

of...  '..  28 

gaging  station  at,  view  of   26 

Wallkill  River  at,  curves  of  equal  Ve- 

locity  on,  diagram  showing ...  30 

discharge  measurements  of  100-101 

gage  heights  of   90-91 

horizontal  velocity  curves  on,  dia- 
gram showing   30 

ice  cover  and  curves  of  equal  ve- 
locity on,  diagram  showing. . .  48 
velocities  in  vertical  sections  on. 

tables  showing    37-38,45 

New  York  City,  gaging  stations  near   13 

water  supply  of,  proposed  sources  of.  12-13 
Newell,  F.  H.,  letter  of  transmittal  by...  7 

Place,  A.  E.,  work  in  ^  harge  of   27 

Platinum-cobalt  method  of  measuring 

color,  description  of  73»-76 

Platinum- wire  process  for  determining 
turbidity,  method  of  applica- 
tion of   69-73 

Powell,  A.  O. ,  work  of   62 

Price  electric  current  meter,  plate  show- 
ing .   20 

Quality  of  river  water,  discussion  of  67-86 

Rafter,  (4.  W.,  reference  to   19 

River  channels,  velocity  in,  methods  of 

measuring   14-20 

Rod  floats,  method  of  using,  to  determine 

velocity   17-18 

Rondout  Creek,  alkalinity  observations 

on.diagranishowing  resultsof .  K 
color  observations  on,  diagram  show- 
ing results  of   74 

discharge  measurements  of  98-100 


INDEX. 


107 


Page. 

Rondout  Creek,  gage  heights  of   89 

gaging  station  on,  view  and  descrip- 
tion of   28 

hardness  observations  on,  diagram 

showing  results  of   78 

quality  of  water  of.  table  showing  78-80 

turbidity  observations  on,  diagram 

showing  results  of   7(1 

velocities  in  vertical  sections  on,  ta- 


bles showing   85-36,46 

under  ice.  tables  showing. . .  56-57.63,64 


under  ice  broken  and  tilted,  tables 

showing  

66,67 

velocity  at  mid  depth  and  mean  ve- 

locity on,  relation  between ... 

44) 

vertical  velocity  curve  for,  diagram 

showing  

24 

under  ice  cover,  diagram  showing 

61 

Rosendale.  gaging  station  at,  view  and 

description  of  

28 

Rondout  Creek  at,  discharge  measure- 

inentsof   98-100 

gage  heights  of   89 

velocities  in  vertical  sections  on, 

tables  showing   35-86, 45 

Rough  bed.  effect  of.  on  velocities  in  ver- 
tical sections   46-17 

Sacramento  River.  California,  relation  of 

mean  and  surface  velocity  on.  28 
San  Gabriel  River.  California,  relation  of 

mean  and  surface  velocity  on.  24 
S  anta  Ana  River.  California,  relation  of 

surface  and  mean  velocity  on.  24 

Schlecht.  W.  W..  work  in  charge  of   27 

Smooth  bed.  effect  of,  on  velocities  in 

vertical  sections   46-47 

South  Cairo.  Catskill  Creek  at,  discharge 

measurements  of   £6 

Catskill  Creek  at.  gage  heights  of   87 

velocities  in  vertical  sections  on. 

tables  showing   39-40. 45 

gaging  station  at.  description  of  27-28 

view  of..    26 

Stearns.  F.  P..  cited  on  surface  velocity..  21 
Stearns.  F.  P..  and  Fteley,  A.,  reference 

to   19 

Subsurface  floats,  method  of  using,  to 

determine  velocity   16-17 

Surface  floats,  methods  of  using,  to  de- 
termine velocity   15-16 

Sweetwater  reservoir,  California,  lack 

of  water  in   10 

Tenmile  River,  alkalinity  observations 
on.  diagram  showing  results 

of   76 

color  observations  on.  diagram  show- 
ing results  of   74 

discharge  measurements  of   103 

gage  heights  of   92-98 

gaging  station  on.  description  of   29 

hardness  observations  on,  diagram 

showing  results  of   78 

quality  of  water  of.  table  showing  ...  82 
turbidity  observations  on,  diagram 

showing  results  of   70  | 


I 'aire. 


Tenmile  River,  velocities  in  vertical  sec- 
tions on.  tables  showing   i'i.  45 

velocity  at  mid  depth  and  mean  ve- 
locity on,  relation  between...  46 
vertical  velocity  curve  for,  diagram 

showing   24 

Tube  floats,  methods  of  using  to  deter- 
mine velocity   17-18 

Tubes  for  determining  color,  method  of 

filling  and  holding   75 

plate  showing    72 

Tuolumne  River.  California,  relation  of 

mean  and  surface  velocity  on. .  23 
Turbid  water,  color  of,  method  of  deter- 
mining    75 

Turbidity,  determination  of   68-73 

of  streams  discussed,  diagram  show- 
ing result  of   70 

tables  showing   77-85 

platinum-wire  process  for  determin- 
ing, method  of  application  of  .  69-73 

standard  of     69 

stick  for  determining,  view  of   86 

Velocities  in  vertical  sections,  tables  show- 
ing  32-4? 

Velocity  in  river  channels,  methods  of 

measuring   14-20 

point  of  mean,  depth  from  surface  to.  20-21 

relation  of  mean  to  mid  depth   46 

to  surface    23-26 

Velocity  curves,  horizontal,  on  Wallkill 

River,  diagram  showing   30 

Velocity  curves,  vertical,  description  of, 

on  streams  without  ice  cover.  20-47 

diagram  showing   24 

form  of     22-23 

Vernon-Harcourt.  L.  F.,  cited  on  relation 

of  mean  to  vertical  velocity  ..  26 
Vertical  sections,  velocities  in,  tables 

showing      32-47 

Vertical  velocity,  relation  of  mean  to  sur- 
face   23-26 

Vertical  velocity  curves,  description  of, 

on  streams  without  ice  cover.  20-47 

diagram  showing    24 

form  of   22-23 

stations  for  obtaining  27-29 

Wallkill  River,  alkalinity  observations 
on,  diagram  showing  results 

of    76 

color  observations  on,  diagram  show- 
ing results  of   74 

discharge  measurements  of   100-10] 

equal  velocity  curves  on.  diagram 

showing..  .'   30 

gage  heights  of   90-91 

gaging  station  on,  description  of   28 

view  of   26 

hardness  observations  on.  diagram 

show  1  n  g  results  of   78 

horizontal  velocity  curves  on.  dia- 
gram showing   .j0 

ice  <  >  »ver  and  curve- 1  if  equal  veli  ><-ity 

on.  diagram  showing   4> 

quality  of  water  of,  table  showing . . .  81-82 


108 


INDEX. 


Page. 

Wallkill  River,  turbidity  observations  on. 

diagram  showiifg  results  of . . .  70 
velocities   in  vertical  sections  on. 

tables  showing   37-38. 45 

under  ice,  tables  showing. . .  50-53. 63,  64 
under  ice,  broken  and  tilted,  tables 

showing   65,07 

velocity  at  mid  depth  and  mean  ve- 
locity on,  relation  between   46 

vertical  velocity  curve  for,  diagram 

showing   24 


Page. 

Wallkill  River,  vertical  velocity  curve 
for,  with  ice  cover,  diagram 

showing  60,61 

"Warm  Springs,  Cal.,  Santa  Ana  River 
at,  relation  of  surface  and 

mean  veloc  ity  on . . .  i   24 

Water  powers,  value  and  utilization  of . .  9-10 
Weirs,  use  of,  in  determining  velocity  . . .  18-19 

Whipple,  G.  C.  color  disks  rated  by   74 

Whipple,  G.  C,  and  Jackson,  D.  D., 

reference  to   71,72 


o 


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[Take  this  Leaf  out  and  paste  the  separated  titles  upon  throe  of  your  catalogue 
cards.  The  first  and  second  titles  need  no  addition:  over  the  third  write  that 
subject  under  which  you  would  place  the  book  in  your  library.] 


United  States.    Department  of  the  interior.    (U.  S.  geological 
survey.) 

Water-Supply  and  Irrigation  Paper  No.  70  Series  L.  Quality 
of  water.  4;  Series  M.  Methods  of  hydrographic  investigation, 
3  |  Department  of  the  interior  |  United  States  geological  sur- 
vey |  Charles  D.  Walcott.  director  |  —  j  Observations  on  the 
flow  of  rivers  |  in  the  |  vicinity  of  New  York  City  |  by  |  Henry 
Albert  Pressey  |  [Vignette]  | 

Washington  |  government  printing  office  |  15)03 

8°.   108  pp.,  13  pis. 


Pressey  (Henry  Albert). 

Water-Supply  and  Irrigation  Paper  No.  70  Series  L.  Quality 
oJ#water.  4;  Series  M,  Methods  of  hydrographic  investigation, 
3  |  Department  of  the  interior  |  United  States  geological  sur- 
vey |  Charles  D.  Walcott.  director  |  —  |  Observations  on  the 
flow  of  rivers  |  in  the  |  vicinity  of  New  York  City  |  by  |  Henry 
Albert  Pressey  |  [Vignette]  | 

Washington  |  government  printing  office  |  1903 

8°.   108  pp.,  13  pis. 


Water-Supply  and  Irrigation  Paper  No.  76  Series  L.  Quality 
of  water.  4;  Series  M.  Methods  of  hydrographic  investigation, 
3  j  Department  of  the  interior  |  United  States  geological  sur- 
vey |  Charles  D.  Walcott.  director  |  —  |  Observations  on  the 
flow  of  rivers  |  in  the  |  vicinity  of  New  York  City  |  by  |  Henry 
Albert  Pressey  |  [Vignette]  | 

Washington  |  government  printing  office  |  1903 

8°.   10S  pp.,  13  pis. 


